Green Century Funds

Prospectus

November 28, 2022

Balanced Fund

Individual Investor Class: GCBLX

Institutional Class: GCBUX

Equity Fund

Individual Investor Class: GCEQX

Institutional Class: GCEUX

MSCI

International

Index Fund

Individual Investor Class: GCINX

Institutional Class: GCIFX

As with all mutual funds, the Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Green Century Capital Management, Inc. (Green Century Capital Management or Green Century) is the investment adviser to the Green Century Funds (the Funds.)

TABLE OF CONTENTS


SUMMARY SECTION
Green Century Balanced Fund			1
Green Century Equity Fund			13
Green Century MSCI International Index Fund			22
The Green Century Funds			33

ADDITIONAL INFORMATION ABOUT THE FUNDS’ INVESTMENT OBJECTIVES, STRATEGIES AND RISKS
Green Century Balanced Fund			35
Green Century Equity Fund			40
Green Century MSCI International Index Fund			42
The Green Century Funds			44

ENVIRONMENTALLY RESPONSIBLE INVESTING
The Green Century Funds’ Environmental Standards			46
Advocates for Corporate Environmental Responsibility			48
The Green Century Funds Support Not-for-Profit Advocacy Organizations			48

MANAGEMENT OF THE GREEN CENTURY FUNDS
Green Century Balanced Fund			49
Green Century Equity Fund			50
Green Century MSCI International Index Fund			51
The Green Century Funds			52

YOUR ACCOUNT
Contact Us			55
How to Invest			55
Types of Accounts			56
Choosing a Share Class			57
Account Minimums			57
How to Purchase Shares			58
How to Sell Shares (Redemptions)			62
Important Information About Redemptions			63
Online Services			64
Transaction Information			65
Shareholder Account Statements			69
Dividends and Taxes			69
Valuation of Shares			71
Shares and Voting Rights			73

FINANCIAL HIGHLIGHTS
Green Century Balanced Fund			74
Green Century Equity Fund			75
Green Century MSCI International Index Fund			76

PRIVACY POLICY (not part of the Prospectus)			77

GREEN CENTURY BALANCED FUND SUMMARY SECTION

Investment Objective

The Green Century Balanced Fund seeks capital growth and income from a diversified portfolio of stocks and bonds which meet Green Century’s standards for corporate environmental responsibility.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. If you invest in shares of the Fund through an investment professional or financial intermediary, that investment professional or financial intermediary may charge you a commission in an amount determined and separately disclosed to you by that investment professional or financial intermediary.



	Individual Investor Class	Institutional Class
Shareholder Fees (fees paid directly from your investment)
Maximum Sales Charge (Load) Imposed on Purchases	None		None
Maximum Deferred Sales Charge (Load)	None		None
Redemption Fee (as a percentage of an amount redeemed within 60 days of purchase)	2.00%		2.00%
Wire Redemption Fee/Overnight Delivery Fee (if such services are requested)	$10/$30		$10/$30

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.63%		0.63%
Distribution (12b-1) Fees	None		None
Other Expenses:
Administrative Fees	0.83%		0.53%
Other Fees	None		None
Total Annual Fund Operating Expenses	1.46%		1.16%

Example

This example is intended to help you compare the costs of investing in the Fund with the cost of investing in other mutual funds. This example assumes that: (1) you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods; (2) your investment has a 5%

return each year; and (3) the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:



	1 Year	3 Years	5 Years	10 Years
Individual Investor Class	$149	$462	$797	$1,746
Institutional Class	$118	$368	$638	$1,409

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 9% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests primarily in the stocks and bonds of U.S. companies the Fund’s Adviser, Green Century Capital Management (Green Century), believes are environmentally responsible and sustainable. Green Century defines its standard for environmentally responsible and sustainable as seeking to provide an opportunity to invest in a way that avoids environmentally dangerous industries which impose onerous costs on society and the planet. There is no predetermined percentage of assets allocated to either stocks or bonds, although the Fund will generally invest at least 25% of its net assets in bonds and may not invest more than 75% of its net assets in stocks.

The Fund seeks to promote environmentally responsible corporate behavior, a cleaner environment and a sustainable economy by investing its assets in companies that Green Century believes are environmentally responsible and sustainable. Green Century applies rigorous selection criteria to identify such companies, which may include, but are not limited to, those that:

•

Demonstrate a commitment to preserving and enhancing the environment as evidenced by the products they make and the services they provide;

•

Make positive contributions toward actively promoting a healthier environmental future, including companies that produce renewable energy products, help conserve water, promote sustainable agriculture, and those that offer effective remedies for existing environmental problems;

•

Strive to openly disclose their policies and performance on critical environmental criteria;

•

Respond positively to shareholder advocacy on environmental, social and governance (ESG) issues.

The Fund also seeks to work with the companies in which it invests to adopt stronger environmental policies for their operations and supply chains.

Green Century believes that companies that seek to manage their environmental risks may enjoy competitive advantages from cost reductions, quality improvements, profitability enhancements and access to expanding and new growth markets. Further, Green Century believes that companies that are responsible towards the environment are more likely to act ethically and maintain the trust of their shareholders.

Green Century believes that environmentally dangerous industries impose onerous costs on society and the planet and seeks to provide an opportunity to invest in a way that avoids them; thus at various times the Fund may not be invested in certain companies and industries Green Century believes threaten a sustainable global environment and public health. The Balanced Fund does not intend to invest in companies that primarily:

•

Explore for, extract, produce, manufacture or refine coal, oil or gas or produce or transmit electricity derived from fossil fuels or transmit natural gas or have material carbon reserves;

•

Are engaged in the production of nuclear energy or the manufacture of nuclear equipment to produce nuclear energy or nuclear weapons, in the belief that these products are unacceptably threatening to a sustainable global environment;

•

Are engaged in the manufacture of tobacco products, which are linked to air pollution, deforestation, and plastic pollution, as well as health problems;

•

Serve as factory farms, which pollute our drinking water and overuse medically important antibiotics;

•

Are involved in genetically modified organisms (GMOs) whose use has led to increased use of toxic herbicides;

•

Produce firearms or military weapons; or

•

Are engaged in gambling and alcohol.

The Fund may invest in growth and value stocks of any market capitalization. The Fund may be more heavily weighted in growth stocks. The Fund’s Subadviser uses quantitative measurements in combination with in-house and third-party research to analyze the stocks of companies identified using Green Century’s environmental criteria, and the Subadviser’s own proprietary ESG integrated investment process, and includes in the Fund’s portfolio those companies that appear to possess superior earnings growth prospects and whose stock prices, in the Subadviser’s opinion, do not accurately reflect the companies’ value. The Subadviser’s in-house research consists of an internally generated analysis using its proprietary investment process. Third-party information providers for both financial and ESG data currently include Bloomberg, L.P., MSCI Inc. and FactSet. The Subadviser may sell a stock in the Fund’s portfolio, if, among other reasons, the company no longer meets the Fund’s environmental standards or the stock no longer meets the Fund’s investment criteria or becomes overvalued relative to the long-term expectation for its stock price.

As a baseline eligibility process, the Subadviser performs an ESG-integrated fundamental research process which includes both industry benchmarking and in-depth company analyses that covers both quantitative and qualitative considerations. In terms of industry reviews, the Subadviser conducts an industry benchmarking evaluation using ESG data weighted according to specific factors deemed by the Subadviser to have the most financial impact for the industry. In terms of the company review, the Subadviser conducts an in depth ESG analysis that evaluates the scope and integrity of a company’s products, policies, and practices related to ESG issues. The ESG criteria reviewed by the Subadviser reflect a variety of key sustainability issues that can influence company risks and opportunities. The ESG criteria implemented by the Subadviser may differ between industries.

The bonds the Fund invests in may be of any maturity. While the Fund’s fixed income investments will be primarily invested in investment grade bonds, the Fund may invest up to 35% of its net assets in high yield, below investment grade bonds, commonly known as “junk bonds.” The Fund’s fixed income investments

consist primarily of corporate bonds, U.S. Government securities, securities issued by supra-national or foreign domiciled entities, municipal securities, and mortgage-related securities, and may include bonds also determined to be “green” by the Subadviser based on the use of proceeds supporting climate change mitigation and adaptation, among other environmental goals.

In general, fixed income securities are included in the Fund’s portfolio to balance or offset risks associated with the Fund’s investment in stocks. Fixed income investments are evaluated using the Fund’s environmental criteria. Issuer-specific financial evaluation of fixed income investments focuses on an issuer’s cash flow, interest rate coverage, and other measures of its ability to meet its future income and principal repayment commitments. In addition, each fixed income investment is evaluated with respect to its credit quality and its overall exposure to interest rate risk.

The Fund may invest up to 30% of its assets in equity and debt securities of non-U.S. issuers.

Principal Risks

You may lose money by investing in the Fund. As with any mutual fund, there can be no guarantee that the Fund will achieve its objective. The following is a summary description of certain risks of investing in the Fund:

Market Risk. The market prices of securities, or other assets held by the Fund may fall, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic or political conditions, recessions, inflation, changes in interest or currency rates, lack of liquidity in the bond markets, the spread of infectious illness or other public health issues, armed conflict, market disruptions caused by tariffs, trade disputes, sanctions or other government actions, or other factors or adverse investor sentiment. If the market prices of the Fund’s securities and assets fall, the value of your investment will go down. A change in financial condition or other event affecting a single issuer or market may adversely impact securities markets as a whole. Rates of inflation have recently risen. The value of assets or income from an investment may be worth less in the future as inflation decreases the value of money. As inflation increases, the real value of the Fund’s assets can decline as can the value of the Fund’s distributions.

Changes in market conditions will not typically have the same impact on all types of securities. The market prices of securities may fall due to factors affecting a particular issuer, industry or the securities market as a whole. In the past decade, financial markets throughout the world have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. Governmental and non‑ governmental issuers have defaulted on, or been forced to restructure, their debts. These conditions may continue, recur, worsen or spread. Events that have contributed to these market conditions include, but are not limited to major cybersecurity events; geopolitical events (including wars, terror attacks and economic sanctions); measures to address budget deficits; downgrading of sovereign debt; changes in oil and commodity prices; dramatic changes in currency exchange rates; global pandemics; and public sentiment. The global pandemic of the novel coronavirus respiratory disease designated COVID‑19 has resulted in major disruption to economies and markets around the world, including the United States. Global financial markets have experienced extreme volatility and severe losses, and trading in many instruments has been disrupted. Liquidity for many instruments has been greatly reduced for periods of time. Some sectors of the economy and individual issuers have experienced particularly large losses. These circumstances may

continue for an extended period of time, and may continue to affect adversely the value and liquidity of the Fund’s investments. Following Russia’s invasion of Ukraine, Russian securities have lost all, or nearly all, their market value. Other securities or markets could be similarly affected by past or future geopolitical or other events or conditions.

Governments and central banks, including the U.S. Federal Reserve, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. These actions have resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time. Although they have started to increase, interest rates are still very low, which means there is more risk that they may go up. U.S. Federal Reserve or other U.S. or non‑U.S. governmental or central bank actions, including increases or decreases in interest rates, or contrary actions by different governments could negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the Fund invests. Policy and legislative changes in the United States and in other countries are affecting many aspects of financial regulation and these and other events affecting global markets, such as the United Kingdom’s exit from the European Union (or Brexit), potential trade imbalances with China or other countries, or sanctions or other government actions against Russia, other nations or individuals or companies (or their countermeasures), may in some instances contribute to decreased liquidity and increased volatility in the financial markets. The impact of these changes on the markets, and the implications for market participants, may not be fully known for some time.

Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, armed conflict including Russia’s military invasion of Ukraine, terrorism, natural disasters, infectious illness or other public health issues, cybersecurity events, supply chain disruptions, sanctions against Russia, other nations or individuals or companies and possible countermeasures, and other circumstances in one country or region could have profound impacts on other countries or regions and on global economies or markets. As a result, whether or not the Fund invests in securities of issuers located in or with significant exposure to the countries or regions directly affected, the value and liquidity of the Fund’s investments may be negatively affected.

Environmentally Responsible Investing Risk. The Fund’s environmental criteria limit the available investments compared with funds with no such criteria. Under certain economic conditions, this could cause the Fund’s investment performance to be worse or better than similar funds with no such criteria. The Subadviser may use third party ESG ratings information that it believes to be reliable, but such information may not be accurate or complete, or may be biased.

Portfolio Selection Risk. The Subadviser’s judgment about a particular security or issuer, or about the economy or a particular sector, region, market segment or industry, or about an investment strategy, may prove to be incorrect or may not produce the desired results, or there may be imperfections, errors or limitations in the models, tools and information used by the Subadviser.

Equity Securities Risk. The Fund is heavily invested in stocks. Like all funds invested in stocks, the Fund’s share price will fluctuate daily depending on the performance of the companies that comprise the Fund’s investments, the general market and the economy overall. After you invest, the value of your shares may be less than what you paid for them.

Small- and Mid‑Cap Companies Risk. The Fund may be invested in small- and mid‑cap companies which involve greater risk than investing in the stocks of larger, more established companies. Small- and mid‑cap companies may lack the management experience, financial resources and product diversification of large companies and the frequency and volume of their trading may be less than that of larger companies. Therefore, securities of small- and mid‑cap companies may be subject to wider and more erratic price fluctuations. Compared to large‑cap companies, small‑cap and mid‑cap companies, and the market for their equity securities, may be more sensitive to changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession, experience sharper swings in market values, have limited liquidity, be harder to value or to sell at the times and prices the Subadviser thinks appropriate, and offer greater potential for gain and loss.

Interest Rate Risk. The market prices of the Fund’s fixed income securities may fluctuate significantly when interest rates change. When interest rates rise, the value of fixed income securities, and therefore the value of your investment in the Fund, generally goes down. A rise in rates tends to have a greater impact on the prices of longer term or duration securities. In recent years interest rates and credit spreads in the U.S. have been at historic lows, which means there is more risk that they may go up. The U.S. Federal Reserve has recently started to raise certain interest rates. A general rise in interest rates could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions from the Fund. During periods of rising interest rates, the average life of certain types of fixed income securities may be extended because of slower than expected principal payments. This may lock in a below market interest rate, increase the security’s duration (a measure of the underlying portfolio’s price sensitivity to changes in prevailing interest rates) and reduce the value of the security. The maturity of a security may be significantly longer than its effective duration. A security’s maturity and other features may be more relevant than its effective duration in determining the security’s sensitivity to other factors affecting the issuer or markets generally, such as changes in credit quality or in the yield premium that the market may establish for certain types of securities (sometimes called “credit spread”). In general, the longer its maturity the more a security may be susceptible to these factors. When the credit spread for a fixed income security goes up or “widens,” the value of the security will generally go down. When interest rates decline, investments made by the Fund may pay a lower interest rate, which would reduce income received and distributed by the Fund. Also, when interest rates go down, the Fund’s yield will decline. During periods of declining interest rates, the issuer of a fixed income security (or borrowers in a pool of loans) may prepay principal earlier than scheduled, forcing the Fund to reinvest in lower yielding securities. The Fund also may lose any premium it paid on the security.

Credit Risk. If an issuer or guarantor of a fixed income security held by the Fund or a counterparty to a financial contract with the Fund defaults on its obligation to pay principal and/or interest, has its credit rating downgraded or is perceived to be less creditworthy, becomes insolvent or files for bankruptcy, or the credit quality or value of any underlying assets declines, the value of your investment will decline. Changes in actual or perceived creditworthiness may occur quickly. The fund could be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty.

LIBOR Risk. The Fund’s investments, payment obligations and financing terms may be based on floating rates, such as LIBOR (London Interbank Offered Rate) or Secured Overnight Financing Rate (SOFR). ICE Benchmark Administration, the administrator of LIBOR, ceased publication of most LIBOR settings on a

representative basis at the end of 2021 and is expected to cease publication of a majority of U.S. dollar LIBOR settings on a representative basis after June 30, 2023. In addition, global regulators have announced that, with limited exceptions, no new LIBOR-based contracts should be entered into after 2021. The transition away from LIBOR may lead to increased volatility and illiquidity in markets that currently rely on LIBOR and may adversely affect the fund’s performance. The transition may also result in a reduction in the value of certain LIBOR-based investments held by the fund or reduce the effectiveness of related transactions such as hedges.

High Yield or “Junk” Bond Risk. Debt securities that are below investment grade, “junk bonds,” are speculative, have a higher risk of default or are already in default, tend to be less liquid and are more difficult to value than higher grade securities. Junk bonds tend to be volatile and more susceptible to adverse events and negative sentiments.

U.S. Government Agency Obligations Risk. Government sponsored entities such as Federal National Mortgage Association (Fannie Mae), Federal Home Loan Mortgage Corporation (Freddie Mac) and the Federal Home Loan Banks (FHLBs), although chartered or sponsored by Congress, are not funded by congressional appropriations and the debt and mortgage-backed securities issued by them are neither guaranteed nor issued by the U.S. government. Although the U.S. government has provided financial support to Fannie Mae and Freddie Mac in the past, there can be no assurance that it will support these or other government sponsored entities in the future.

Municipal Securities Risk. The municipal bond market can be susceptible to unusual volatility, particularly for lower-rated and unrated securities. Liquidity can be reduced unpredictably in response to overall economic conditions or credit tightening. Municipal issuers may be adversely affected by rising health care costs, increasing unfunded pension liabilities, and by the phasing out of federal programs providing financial support. Unfavorable conditions and developments relating to projects financed with municipal securities can result in lower revenues to issuers of municipal securities, potentially resulting in defaults. Issuers often depend on revenues from those projects to make principal and interest payments. The value of municipal securities can also be adversely affected by changes in the financial condition of one or more individual municipal issuers or insurers of municipal issuers, regulatory and political developments, tax law changes or other legislative actions, and by uncertainties and public perceptions concerning these and other factors. Municipal issuers may be more susceptible to downgrades or defaults during recessions or similar periods of economic stress. Financial difficulties of municipal issuers may continue or worsen, particularly in the event of economic or market turmoil or a recessions.

Mortgage-Related Securities Risk. The value of mortgage-related securities will be influenced by factors affecting the assets underlying such securities. As a result, during periods of declining asset value, difficult or frozen credit markets, swings in interest rates, or deteriorating economic conditions, mortgage-related securities may decline in value, face valuation difficulties, become more volatile and/or become illiquid. These securities are also subject to prepayment and call risk. Some of these securities may receive little or no collateral protection from the underlying assets and are thus subject to the risk of default. The risk of such defaults is generally higher in the case of mortgage-backed investments issued by non‑governmental issuers and those that include so‑called “sub‑prime” mortgages. The structure of some of these securities may be complex and there may be less available information than for other types of debt securities. Upon the

occurrence of certain triggering events or defaults, the Fund may become the holder of underlying assets at a time when those assets may be difficult to sell or may be sold only at a loss.

Risks of Non‑U.S. Investments. Investing in non‑U.S. issuers or in securities of U.S. issuers with significant exposure to foreign markets may involve unique risks compared to investing in securities of U.S. issuers. These risks are more pronounced for issuers in emerging markets or to the extent that the Fund invests significantly in one region or country. These risks may include different financial reporting practices and regulatory standards, less liquid trading markets, currency risks, changes in economic, political, regulatory and social conditions, armed conflict including Russia’s military invasion of Ukraine, and sanctions or other government actions against Russia, other nations or individuals or companies (or their countermeasures), sustained economic downturns, reduction of government or central bank support, inadequate accounting standards, tariffs, tax dispute or other tax burdens, natural disasters, terrorism, nationalization or expropriation of assets, arbitrary application of laws and regulations or lack of rule of law, and investment and repatriation restrictions. Emerging market economies tend to be less diversified than those of more developed countries. They typically have fewer medical and economic resources than more developed countries and thus they may be less able to control or mitigate the effects of a pandemic.

Market Sector Risk. The Fund may hold a large percentage of securities in a single market sector. To the extent the Fund holds a large percentage of securities in a single sector, its performance will be tied closely to and affected by the performance of that sector, and the Fund will be subject to a greater degree to any market price movements, regulatory or technological change, economic conditions or other developments or risks affecting such market sector than a fund without the same focus.

•

Financial Sector Risk. Issuers in the financial sector, such as banks, insurance companies and broker- dealers, may be sensitive to changes in interest rates, credit rating downgrades, decreased liquidity in credit markets, and general economic activity and are generally subject to extensive government regulation.

•

Technology Sector Risk. Securities in the technology sector, such as information technology, communications equipment, computer hardware and software, and office and scientific equipment, are generally subject to risks of rapidly evolving technology, short product lives, rates of corporate expenditures, falling prices and profits, competition from new market entrants, and general economic conditions. They are also heavily dependent on intellectual property rights and may be adversely affected by the loss or impairment of, or inability to enforce, those rights.

Fund may suffer a substantial loss or may not be able to sell at all. Additionally, the market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and the difficulty in purchasing and selling such securities, may be unable to achieve its desired level of exposure to certain sectors. Further, certain securities, once sold, may not settle for an extended period. The Fund will not receive its sales proceeds until that time, which may constrain the Fund’s ability to meet its obligations (including obligations to redeeming shareholders). Liquidity risk may be magnified in an environment of rising interest rates or widening credit spreads in which investor redemptions from fixed income funds may be higher than normal.

Valuation Risk. A significant percentage of the Fund’s securities are valued using a fair value methodology. The sales price the Fund could receive for any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets. These differences may increase significantly and affect Fund investments more broadly during periods of market volatility. Investors who purchase or redeem Fund shares may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the Fund had not fair-valued securities or had used a different valuation methodology. The Fund’s ability to value its investments may be impacted by technological issues and/or errors by pricing services or other third party service providers.

Redemption Risk. The Fund may experience periods of heavy redemptions that could cause the Fund to liquidate its assets at inopportune times or at a loss or depressed value, particularly during periods of declining or illiquid markets. Redemption risk is greater to the extent that the Fund has investors with large shareholdings, short investment horizons, or unpredictable cash flow needs. In addition, redemption risk is heightened during periods of overall market turmoil. The redemption by one or more large shareholders of their holdings in the Fund could hurt performance and/or cause the remaining shareholders in the Fund to lose money. Further, if one decision maker has control of Fund shares owned by separate Fund shareholders, including clients or affiliates of the Fund’s Adviser, redemptions by these shareholders may further increase the Fund’s redemption risk. If the Fund is forced to liquidate its assets under unfavorable conditions or at inopportune times, the value of your investment could decline.

Cybersecurity Risk. Cybersecurity failures by or breaches of the Fund’s Adviser, Subadviser, transfer agent, distributor, custodian, fund accounting agent or other service providers may disrupt Fund operations, interfere with the Fund’s ability to calculate its NAV, prevent Fund shareholders from purchasing, redeeming or exchanging shares or receiving distributions or receiving timely information regarding the Fund or their investment in the Fund, cause loss of or unauthorized access to private shareholder information, and result in financial losses to the Fund and its shareholders, regulatory fines, penalties, reputational damage, or additional compliance costs. Substantial costs may be incurred in order to prevent any cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result.

These and other risks are discussed in more detail in “Additional Information About the Funds’ Investment Objectives, Strategies and Risks” in this Prospectus and in the Statement of Additional Information.

Performance

The bar chart and the average annual total return table below provide some indication of the risks of investing in the Fund by showing how the Fund has performed in the past. The bar chart shows changes in the performance of the Individual Investor Class of the Fund from year to year. The table shows how the average annual total returns of each class of the Fund for 1, 5 and 10 year periods compare with the returns of broad measures of market performance, including the S&P 500 Index and the Custom Balanced Index (the Custom Balanced Index is comprised of a 60% weighting in the S&P 1500 Index and a 40% weighting in the BofA Merrill Lynch 1-10 Year U.S. Corporate & Government Index). The table also compares the performance of each class of the Fund to the Lipper Balanced Fund Index, a universe of mutual funds with investment objectives similar to that of the Fund.

The Fund’s past performance (before and after taxes) does not necessarily indicate how it will perform in the future. Updated performance information is available on the Fund’s website, www.greencentury.com/fund-performance/, or by calling 1-800-934-7336.

Annual Total Returns for Years Ended December 31

During the period shown, the Fund’s Individual Investor Class best quarterly performance was 14.28%, for the quarter ended 6/30/20. The Fund’s Individual Investor Class worst quarterly performance was -12.74%, for the quarter ended 3/31/20.

As of September 30, 2022, the year-to-date return for the Fund’s Individual Investor Class was -20.56%.

Average Annual Total Returns For the Periods Ended December 31, 2021



	1 Year			5 Years			10 Years			Since Inception (March 18, 1992)
Green Century Balanced Fund – Individual Investor Class
Return before taxes		16.43	%		12.49	%		10.90	%		7.66	%

Return after taxes on distributions		15.36	%		11.78	%		10.26	%		6.82	%

Return after taxes on distributions and sale of Fund shares		10.49	%		9.87	%		8.88	%		6.26	%

Green Century Balanced Fund – Institutional Class
Returns before taxes		16.74	%		12.57	%		10.93	%		7.67	%

Custom Balanced Index (reflects no deduction for fees, expenses or taxes)		15.81	%		12.05	%		10.83	%		N/A

Lipper Balanced Fund Index (reflects no deduction for fees, expenses or taxes)		13.18	%		10.80	%		9.55	%		7.79	%

S&P 500 Index (reflects no deduction for fees, expenses or taxes)		28.71	%		18.47	%		16.55	%		10.78	%

Institutional Shares were offered as of November 28, 2020. The Institutional Class performance prior to November 28, 2020 reflects the performance of the Fund’s Individual Investor Class. The after-tax returns are shown for the Individual Investor Class of the Fund and the after-tax returns for the Institutional Class of the Fund will vary. The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

Management

Investment Adviser: Green Century Capital Management, Inc.

Investment Subadviser: Trillium Asset Management

Portfolio Managers: Cheryl Smith, CFA, Ph.D, Economist and Portfolio Manager (portfolio manager since 2005), Paul Hilton, CFA, Portfolio Manager and Research Analyst (portfolio manager since 2018), and Matthew Patsky, CFA, Chief Executive Officer and Portfolio Manager of Trillium (portfolio manager since 2009) are jointly responsible for the day-to-day portfolio management of the Fund.

For important information on how to buy and sell shares in the Fund, taxes and financial intermediary compensation, please turn to “Green Century Funds Summary Section” on page 33 of this Prospectus.

GREEN CENTURY EQUITY FUND SUMMARY SECTION

Investment Objective

The Green Century Equity Fund seeks to achieve long-term total return which matches the performance of an index comprised of the stocks of companies selected based on environmental, social and governance (ESG) criteria.

Fees and Expenses of the Fund



	Individual Investor Class	Institutional Class
Shareholder Fees (fees paid directly from your investment)
Maximum Sales Charge (Load) Imposed on Purchases	None	None
Maximum Deferred Sales Charge (Load)	None	None
Redemption Fee (as a percentage of an amount redeemed within 60 days of purchase)	2.00%	2.00%
Wire Redemption Fee/Overnight Delivery Fee (if such services are requested)	$10/$30	$10/$30

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.22%	0.22%
Distribution (12b-1) Fees	None	None
Other Expenses:
Administrative Fees	1.03%	0.73%
Other Fees	None	None
Total Annual Fund Operating Expenses	1.25%	0.95%

Example

return each year; and (3) the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:



	1 Year	3 Years	5 Years	10 Years
Individual Investor Class	$127	$397	$686	$1,511
Institutional Class	$97	$303	$525	$1,166

Portfolio Turnover

Principal Investment Strategies

The Fund invests substantially all of its assets in the common stocks which make up the MSCI KLD 400 Social ex Fossil Fuels Index (the KLD400 ex Fossil Fuels Index or the Index), a custom index calculated by MSCI, Inc. The KLD400 ex Fossil Fuels Index is comprised of the common stocks of the approximately 400 companies in the MSCI KLD 400 Social Index (the KLD400 Index), minus the stocks of the companies that:

•

Explore for, extract, produce, manufacture or refine coal, oil or gas;

•

Produce or transmit electricity derived from fossil fuels or transmit natural gas; or

•

Have carbon reserves included in the KLD400 Index.

Companies included in the KLD400 Index are identified based on a review of ESG ratings; the KLD400 Index is composed of companies with what MSCI calculates to have high ESG ratings.

In constructing the KLD400 Index, MSCI ESG Research analyzes a company’s commitment to sustainability across the following ESG issues that focus on the intersection between a company’s core business and the industry-specific issues that may create significant risks and opportunities for the company:

•

Environmental issues, including:

Climate Change: carbon emissions; product carbon footprint; financing environmental impact; and climate change vulnerability.

Natural Capital: water stress; biodiversity and land use; and raw material sourcing.

Pollution and Waste: toxic emissions and waste; packaging material and waste; and electronic waste.

Environmental Opportunities: clean technology; green building; and renewable energy.

•

Social issues, including:

Human Capital: labor management; health and safety; human capital development; and supply chain labor standards.

Product Liability: product safety and quality; chemical safety; financial product safety; privacy and data security; responsible investment; and insuring health and demographic risk.

Stakeholder Opposition: controversial sourcing.

Social Opportunities: access to communication; access to finance; access to health care; and opportunities in nutrition and health.

•

Governance issues, including:

Corporate Governance: board; pay; ownership and accounting.

Corporate Behavior: business ethics; anti-competitive practices; corruption and instability; financial system instability; and tax transparency.

MSCI ESG Research’s process in constructing the KLD400 Index includes the identification of the above key issues by industry; measuring a company’s risk exposure for each key issue; and measuring a company’s risk management for each key issue.

Companies that MSCI ESG Research has determined to have significant business involvement in the following will not be included in the KLD400 Index:

•

Companies that are primarily engaged in the production of nuclear energy or the manufacture of nuclear equipment to produce nuclear energy or nuclear weapons, in the belief that these products are unacceptably threatening to a sustainable global environment.

•

Companies that are primarily engaged in the manufacture of tobacco products, which are linked to air pollution, deforestation, and plastic pollution, as well as health problems.

•

Companies that have a significant business involvement in genetically modified organisms (GMOs) whose use has led to increased use of toxic herbicides.

•

Companies that are in industries that produce firearms or military weapons.

•

Companies that are primarily engaged in gambling, alcohol or adult entertainment

Green Century believes that constructing a Fund’s portfolio based on ESG criteria creates an incentive for companies to become more sustainable. Green Century believes that those companies which seek to manage their ESG risk may be better prepared to avoid reputational, competitive, regulatory and material risks and may benefit financially as a result. Green Century also believes that the growing use of ESG ratings may create an incentive for companies to measure and manage their risks better to secure higher scores on ESG ratings systems.

The Fund buys and sells stocks so that the composition of its securities holdings will correspond, to the extent reasonably practicable, to the composition of securities in the KLD400 ex Fossil Fuels Index. The weightings of the stocks in the KLD400 ex Fossil Fuels Index are based on float-adjusted market capitalizations, which means the largest companies comprise a higher percentage of the KLD400 ex Fossil Fuels Index and the Index is more heavily weighted in large than in small companies. As of September 30, 2022, large-cap U.S. companies (defined as companies with market capitalizations of over $10 billion) represented approximately 96.4% of the market value of the investments of the Fund. To the extent practicable, the Fund will seek a correlation between the weightings of securities held by the Fund and the weightings of the securities of the KLD400 ex Fossil Fuels Index of 0.95 or better. A figure of 1.00 would indicate a perfect correlation. The Fund’s ability to duplicate the performance of the KLD400 ex Fossil Fuels

Index will depend to some extent on the size and timing of cash flows into and out of the Fund as well as the Fund’s expenses.

Under normal circumstances and as a matter of operating policy, the Fund will invest at least 80% of its assets in equity securities and related investments.

Principal Risks

Changes in market conditions will not typically have the same impact on all types of securities. The market prices of securities may fall due to factors affecting a particular issuer, industry or the securities market as a whole. In the past decade, financial markets throughout the world have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. Governmental and non-governmental issuers have defaulted on, or been forced to restructure, their debts. These conditions may continue, recur, worsen or spread. Events that have contributed to these market conditions include, but are not limited to major cybersecurity events; geopolitical events (including wars, terror attacks and economic sanctions); measures to address budget deficits; downgrading of sovereign debt; changes in oil and commodity prices; dramatic changes in currency exchange rates; global pandemics; and public sentiment. The global pandemic of the novel coronavirus respiratory disease designated COVID-19 has resulted in major disruption to economies and markets around the world, including the United States. Global financial markets have experienced extreme volatility and severe losses, and trading in many instruments has been disrupted. Liquidity for many instruments has been greatly reduced for periods of time. Some sectors of the economy and individual issuers have experienced particularly large losses. These circumstances may continue for an extended period of time, and may continue to affect adversely the value and liquidity of the Fund’s investments. Following Russia’s invasion of Ukraine, Russian securities have lost all, or nearly all, their market value. Other securities or markets could be similarly affected by past or future geopolitical or other events or conditions.

resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time. Although they have started to increase, interest rates are still very low, which means there is more risk that they may go up. U.S. Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including increases or decreases in interest rates, or contrary actions by different governments could negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the Fund invests. Policy and legislative changes in the United States and in other countries are affecting many aspects of financial regulation and these and other events affecting global markets, such as the United Kingdom’s exit from the European Union (or Brexit), potential trade imbalances with China or other countries, or sanctions or other government actions against Russia, other nations or individuals or companies (or their countermeasures), may in some instances contribute to decreased liquidity and increased volatility in the financial markets. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Environmental, Social and Governance Investing Risk. The Fund’s environmental, social and governance criteria limit the available investments compared with funds with no such criteria. Under certain economic conditions, this could cause the Fund’s investment performance to be worse or better than similar funds with no such criteria.

Large Cap Companies Risk. Large-cap companies may be unable to respond quickly to new competitive challenges such as changes in technology, and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion. The large-cap companies in which the Fund invests may perform worse than the stock market as a whole.

Small- and Mid-Cap Companies Risk. The Fund may be invested in small- and mid-cap companies which involve greater risk than investing in the stocks of larger, more established companies. Small- and mid-cap companies may lack the management experience, financial resources and product diversification of large companies and the frequency and volume of their trading may be less than that of larger companies. Therefore, securities of small- and mid-cap companies may be subject to wider and more erratic price fluctuations. Compared to large-cap companies, small-cap and mid-cap companies, and the market for their

equity securities, may be more sensitive to changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession, experience sharper swings in market values, have limited liquidity, be harder to value or to sell at the times and prices the Subadviser thinks appropriate, and offer greater potential for gain and loss.

•

Health Care Sector Risk. Industries in the health care sector, such as health care supplies, health care services, biotechnology and pharmaceuticals, may be significantly affected by government regulation and reimbursement rates, approval of products by government agencies, and patent expirations, increases or decreases in the cost of medical products and services and product liability claims, among other factors. Many health care companies are heavily dependent on patent protection, and the expiration of a company’s patent may adversely affect that company’s profitability. Healthcare companies are subject to competitive forces that may result in price discounting, and may be thinly capitalized and susceptible to product obsolescence.

•

Consumer Discretionary Sector Risk. Industries in the consumer discretionary segment, such as consumer durables, hotels, restaurants, media, retailing and automobiles, may be significantly affected by the performance of domestic and international economies, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.

Liquidity Risk. Liquidity risk exists when particular investments are difficult to purchase or sell. When the Fund holds these types of investments, the Fund’s portfolio may be more difficult to value, especially during periods of market turmoil or due to adverse changes in the conditions of a particular issuer. Markets may become illiquid when there are few, if any, interested buyers or sellers or when dealers are unwilling or unable to make a market for certain securities or when dealer market-making capacity is otherwise reduced. During times of market turmoil, there have been, and may be, no buyers for securities in entire asset classes, including U.S. Treasury securities. As a general matter, dealers recently have been less willing to make markets for fixed income securities. When the Fund holds illiquid investments, the Fund may be harder to value, especially in changing markets. Investments by the Fund in below investment grade securities, foreign securities, and corporate loans tend to involve greater liquidity risk. If the Fund is forced to sell or unwind these investments to meet redemptions or for other cash needs or try to limit losses, the Fund may suffer a substantial loss or may not be able to sell at all. Additionally, the market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and the difficulty in purchasing and selling such securities, may be unable to achieve its desired

level of exposure to certain sectors. Further, certain securities, once sold, may not settle for an extended period. The Fund will not receive its sales proceeds until that time, which may constrain the Fund’s ability to meet its obligations (including obligations to redeeming shareholders).

Index Fund Risk. The Fund will invest in the stocks composing the KLD400 ex Fossil Fuels Index regardless of how the Index is performing. It will not shift concentration from one industry to another, or from stocks to bonds or cash, in order to defend against a falling stock market. The Index may, at times, become focused in stocks of a particular sector, category or group of companies. Because the Fund seeks to track the KLD400 ex Fossil Fuels Index, the Fund may underperform the overall stock market.

Non-Correlation Risk. The performance of the Fund and of the KLD400 ex Fossil Fuels Index may vary for a variety of reasons. For example, the Fund incurs operating expenses and portfolio transaction costs not incurred by the Index. In addition, the Fund may not be fully invested in the component securities of the Index.

Valuation Risk. The sales price the Fund could receive for any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair value methodology. These differences may increase significantly and affect Fund investments more broadly during periods of market volatility. Investors who purchase or redeem Fund shares on days when the Fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the Fund had not fair-valued securities or had used a different valuation methodology. The Fund’s ability to value its investments may be impacted by technological issues and/or errors by pricing services or other third party service providers.

Cybersecurity Risk. Cybersecurity failures by or breaches of the Fund’s Adviser, Subadviser, transfer agent, distributor, custodian, fund accounting agent or other service providers may disrupt Fund operations, interfere with the Fund’s ability to calculate its NAV, prevent Fund shareholders from purchasing, redeeming or exchanging shares or receiving distributions or receiving timely information regarding the Fund or their investment in the Fund, cause loss of or unauthorized access to private shareholder information, and result in financial losses to the Fund and its Shareholders, regulatory fines, penalties, reputational damage, or additional compliance costs. Substantial costs may be incurred in order to prevent any cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result.

Performance

The Fund, which commenced operations in September 1995, invested all its assets in an existing separate registered investment company which had the same investment objective as the Fund (the Domini Social Equity Trust) until November 28, 2006. The performance for the period prior to the Fund’s inception reflects the performance of the Domini Social Equity Trust adjusted to reflect the deduction of the charges and expenses of the Fund.

As of April 1, 2014, the Fund invests in the common stocks which make up the MSCI KLD 400 Social ex Fossil Fuels Index. Prior to April 1, 2014, the Fund invested in the common stocks which made up the MSCI KLD 400 Social Index. Performance for periods prior to April 1, 2014 reflects the investment strategy in effect for the Fund during such periods.

Annual Total Returns for Years Ended December 31

During the period shown, the best quarterly performance of the Fund’s Individual Investor Class was 21.21%, for the quarter ended 6/30/20. The worst quarterly performance of the Fund’s Individual Investor Class was -17.07%, for the quarter ended 3/31/20.

As of September 30, 2022, the year-to-date return for the Fund’s Individual Investor Class was -28.21%.

Average Annual Total Returns For the Periods Ended December 31, 2021



	1 Year			5 Years			10 Years			Since Inception (June 3, 1991)
Green Century Equity Fund – Individual Investor Class
Return before taxes		29.70	%		19.39	%		16.26	%		9.85	%

Return after taxes on distributions		29.36	%		19.04	%		15.90	%		9.09	%

Return after taxes on distributions and sale of Fund shares		17.83	%		15.74	%		13.74	%		8.32	%

Green Century Equity Fund – Institutional Class
Return before taxes		30.08	%		19.65	%		16.39	%		9.89	%

S&P 500 Index (reflects no deduction for fees, expenses or taxes)		28.71	%		18.47	%		16.55	%		10.76	%

Institutional Class shares were offered as of April 30, 2018. The Institutional Class performance for periods prior to April 30, 2018 reflects the performance of the Fund’s Individual Investor Class. The after‑tax returns are shown for the Individual Investor Class of the Fund and the after‑tax returns for the Institutional Class of the Fund will vary. The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

Management

Investment Adviser: Green Century Capital Management, Inc.

Investment Subadviser: Northern Trust Investments, Inc. (NTI)

Portfolio Manager: Brent Reeder, Senior Vice President and Director of US Index Equities at NTI (portfolio manager since 2010).

GREEN CENTURY MSCI INTERNATIONAL INDEX FUND SUMMARY SECTION

Investment Objective

The Green Century MSCI International Index Fund seeks to achieve long-term total return which matches the performance of an index comprised of the stocks of foreign companies selected based on environmental, social and governance (ESG) criteria.

Fees and Expenses of the Fund



	Individual Investor Class	Institutional Class
Shareholder Fees (fees paid directly from your investment)
Maximum Sales Charge (Load) Imposed on Purchases	None	None
Maximum Deferred Sales Charge (Load)	None	None
Redemption Fee (as a percentage of an amount redeemed within 60 days of purchase)	2.00%	2.00%
Wire Redemption Fee/Overnight Delivery Fee (if such services are requested)	$10/$30	$10/$30

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.28%	0.28%
Distribution (12b-1) Fees	None	None
Other Expenses:
Administrative Fees	1.00%	0.70%
Other Fees	None	None
Total Annual Fund Operating Expenses	1.28%	0.98%

Example

return each year; and (3) the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:



	1 Year	3 Years	5 Years	10 Years
Individual Investor Class	$130	$406	$702	$1,545
Institutional Class	$100	$312	$542	$1,201

Portfolio Turnover

Principal Investment Strategies

The Fund invests substantially all of its assets in the common stocks which make up the MSCI World ex USA SRI ex Fossil Fuels Index (the World ex USA SRI ex Fossil Fuels Index or the Index), a custom index calculated by MSCI, Inc. The World ex USA SRI ex Fossil Fuels Index is comprised of the common stocks of the companies in the MSCI World ex USA SRI Index (the World ex USA SRI Index), minus the stocks of the companies that:

•

Explore for, extract, produce, manufacture or refine coal, oil or gas;

•

Produce or transmit electricity derived from fossil fuels or transmit natural gas;

•

Have carbon reserves included in the World ex USA SRI (Socially Responsible Investment) Index.

The World ex USA SRI Index includes large and mid‑cap stocks from approximately 22 developed markets countries (excluding the U.S.). The World ex USA SRI Index is a capitalization weighted index that provides exposure to companies with what MSCI calculates to have high ESG ratings.

In constructing the World ex USA SRI Index, MSCI ESG Research analyzes a company’s commitment to sustainability across the following ESG issues that focus on the intersection between a company’s core business and the industry-specific issues that may create significant risks and opportunities for the company:

•

Environmental issues, including:

Climate Change: carbon emissions; product carbon footprint; financing environmental impact; and climate change vulnerability.

Natural Capital: water stress; biodiversity and land use; and raw material sourcing.

Pollution and Waste: toxic emissions and waste; packaging material and waste; and electronic waste.

Environmental Opportunities: clean technology; green building; and renewable energy.

•

Social issues, including:

Human Capital: labor management; health and safety; human capital development; and supply chain labor standards.

Product Liability: product safety and quality; chemical safety; financial product safety; privacy and data security; responsible investment; and insuring health and demographic risk.

Stakeholder Opposition: controversial sourcing.

Social Opportunities: access to communication; access to finance; access to health care; and opportunities in nutrition and health.

•

Governance issues, including:

Corporate Governance: board; pay; ownership and accounting.

Corporate Behavior: business ethics; anti-competitive practices; corruption and instability; financial system instability; and tax transparency.]

MSCI ESG Research’s process in constructing the World ex USA SRI Index includes the identification of the above key issues by industry; measuring a company’s risk exposure for each key issue; and measuring a company’s risk management for each key issue.

Companies that MSCI ESG Research has determined to have significant business involvement in the following will not be included in the World ex USA SRI Index:

•

Companies that are primarily engaged in the manufacture of tobacco products, which are linked to air pollution, deforestation, and plastic pollution, as well as health problems.

•

Companies that have a significant business involvement in genetically modified organisms (GMOs) whose use has led to increased use of toxic herbicides.

•

Companies that are in industries that produce firearms or military weapons.

•

Companies that are primarily engaged in gambling, alcohol or adult entertainment

Green Century believes that constructing a Fund’s portfolio based on ESG criteria creates an incentive for companies to become more sustainable. Green Century believes that those companies which seek to manage their ESG risks may be better prepared to avoid reputational, competitive, regulatory and material risks and may benefit financially as a result. Green Century also believes that the growing use of ESG ratings may create an incentive for companies to measure and manage their risks better to secure higher scores on ESG ratings systems.

The Fund buys and sells stocks so that the composition of its securities holdings will correspond, to the extent reasonably practicable, to the composition of securities in the World ex USA SRI ex Fossil Fuels Index. The weightings of the stocks in the World ex USA SRI ex Fossil Fuels Index are based on float-adjusted market capitalizations, which means the largest companies comprise a higher percentage of the World ex USA SRI ex Fossil Fuels Index and the Index is more heavily weighted in large than in smaller companies. As of September 30, 2022, the World ex USA SRI ex Fossil Fuels Index included companies with market capitalizations between approximately $2 billion and $194 billion. To the extent practicable, the Fund will seek a correlation between the weightings of securities held by the Fund and the weightings of the securities

of the World ex USA SRI ex Fossil Fuels Index of 0.95 or better. A figure of 1.00 would indicate a perfect correlation. The Fund’s ability to duplicate the performance of the World ex USA SRI ex Fossil Fuels Index will depend to some extent on the size and timing of cash flows into and out of the Fund as well as the Fund’s expenses.

Under normal circumstances and as a matter of operating policy, the Fund will invest at least 80% of its assets in the component securities of the World ex USA SRI ex Fossil Fuels Index and may invest in American Depository Receipts, Global Depository Receipts and Euro Depository Receipts representing the component securities of the Index.

Principal Risks

Market Risk. The market prices of securities or other assets held by the Fund may fall, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic or political conditions, recessions, inflation, changes in interest or currency rates, lack of liquidity in the bond markets, the spread of infectious illness or other public health issues, armed conflict, market disruptions caused by tariffs, trade disputes, sanctions or other government actions, or other factors, or adverse investor sentiment. If the market prices of the Fund’s securities and assets fall, the value of your investment will go down. A change in financial condition or other event affecting a single issuer may adversely impact securities markets as a whole. Rates of inflation have recently risen. The value of assets or income from an investment may be worth less in the future as inflation decreases the value of money. As inflation increases, the real value of the Fund’s assets can decline as can the value of the Fund’s distributions.

Governments and central banks, including the U.S. Federal Reserve, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. These actions have resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time. Although they have started to increase, interest rates are still very low, which means there is more risk that they may go up. U.S. Federal Reserve or other U.S. or non‑U.S. governmental or central bank actions, including increases or decreases in interest rates, or contrary actions by different governments could negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the Fund invests. Policy and legislative changes in the United States and in other countries are affecting many aspects of financial regulation and these and other events affecting global markets, such as the United Kingdom’s exit from the European Union (or Brexit), potential trade imbalances with China or other countries, or sanctions or other government actions against Russia, other nations or individuals or companies (or their countermeasures), may in some instances contribute to decreased liquidity and increased volatility in the financial markets. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, armed conflict including Russia’s military invasion of Ukraine, terrorism, natural disasters, infectious illness or public health issues, cybersecurity events, supply chain disruptions, sanctions against Russia, other nations or individuals or companies and possible countermeasures, and other circumstances in one country or region could have profound impacts on other countries or regions and on global economies or markets. As a result, whether or not the Fund invests in securities of issuers located in or with significant exposure to the countries or regions directly affected, the value and liquidity of the Fund’s investments may be negatively affected.

Large Cap Companies Risk. Large‑cap companies may be unable to respond quickly to new competitive challenges such as changes in technology, and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion. The large‑cap companies in which the Fund invests may perform worse than the stock market as a whole.

Mid‑Cap Companies Risk. The Fund may be invested in mid‑cap companies which involve greater risk than investing in the stocks of larger, more established companies. Mid‑cap companies may lack the management experience, financial resources and product diversification of large companies and the frequency and volume of their trading may be less than that of larger companies. Therefore, securities of mid‑cap companies may be subject to wider and more erratic price fluctuations. Compared to large‑cap companies,

small‑cap and mid‑cap companies, and the market for their equity securities, may be more sensitive to changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession, experience sharper swings in market values, have limited liquidity, be harder to value or to sell at the times and prices the Subadviser thinks appropriate, and offer greater potential for gain and loss.

Risks of Non‑U.S. Investments. Investing in non‑U.S. issuers or in securities of U.S. issuers with significant exposure to foreign markets may involve unique risks compared to investing in securities of U.S. issuers. These risks are more pronounced to the extent that the Fund invests significantly in one region or country. These risks may include different financial reporting practices and regulatory standards, less liquid trading markets, currency risks, changes in economic, political, regulatory and social conditions, armed conflict including Russia’s military invasion of Ukraine, and sanctions or other government actions against Russia, other nations or individuals or companies (or their countermeasures), sustained economic downturns, reduction of government or central bank support, inadequate accounting standards, tariffs, tax disputes or other tax burdens, natural disasters, terrorism, nationalization or expropriation of assets, arbitrary application of laws and regulations or lack of rule of law, and investment and repatriation restrictions. Emerging market economies tend to be less diversified than those of more developed countries. They typically have fewer medical and economic resources than more developed countries and thus they may be less able to control or mitigate the effects of a pandemic.

Country Risk. The Fund expects to diversify its investments among issuers with significant exposure to various countries throughout the world but it may hold a large number of securities whose issuers have exposure to a single country, including but not limited to Japan, France, Germany, Canada, Switzerland and the United Kingdom (the “U.K.”). Significant exposure to a single country would increase the risk that economic, political, and social conditions in that country will have a significant impact on Fund performance.

•

The Japanese economy is highly dependent upon international trade, particularly with the United States and other Asian countries. Because of its trade dependence, the Japanese economy is particularly exposed to the risks of currency fluctuation, foreign trade policy and regional and global economic disruption. In the past, Japan’s economic growth rate has remained relatively low, and it may remain low in the future. The Japanese economic growth rate could be impacted by Bank of Japan monetary policies, rising interest rates, tax increases, budget deficits, consumer confidence and volatility in the Japanese yen. Japan’s economy has been adversely affected by trade tariffs, other protectionist measures, competition from emerging economies and the economic conditions of trading partners. Strained foreign relations with neighboring countries (China, South Korea, North Korea and Russia) may not only negatively impact the Japanese economy but also the geographic region as well as globally. Economic growth in Japan is heavily dependent on continued growth in international trade, government support of the financial services sector, among other troubled sectors, and consistent government policy. In addition, the Japanese economy has been adversely affected by certain structural issues, including an aging population, significant non‑performing loan portfolios at major financial institutions, substantial government deficits, low domestic consumption and natural and environmental disasters.

•

The French economy, including demand for French exports, may be adversely affected by the U.K.’s withdrawal from the European Union (“EU”). As a result, the French economy may experience

adverse trends due to concerns about a prolonged economic downturn, potential weakness in exports, high rates of unemployment and rising government debt levels. The French economy is dependent on agricultural exports, and as a result, is susceptible to fluctuations in demand for agricultural products. France has experienced several terrorist attacks in the past several years.

•

Germany has an industrial and export dependent economy and relies heavily on trade with key trading partners, including the Netherlands, China, the U.S., the U.K., France, Italy and other European countries. Changes in the price or demand for German exports may have an adverse impact on Germany’s economy. In addition, heavy regulation of labor, energy and product markets in Germany may have an adverse impact on German issuers. Such regulations may negatively impact economic growth or cause prolonged periods of recession. Ongoing concerns regarding the economic health of the EU have negatively impacted the earnings of German financial services companies.

•

The U.K. has one of the largest economies in Europe, and the U.S. and other European countries are substantial trading partners of the U.K. As a result, the U.K.’s economy may be impacted by changes to the economic condition of the U.S. and other European countries. The U.K.’s economy will also be significantly affected by the U.K.’s exit from the EU. The precise impact on the U.K’s economy as a result of its departure from the EU depends to a large degree on its ability to conclude favorable trade deals with the EU and other countries and offset the increased costs of trade resulting from the U.K.’s loss of its membership in the EU single market. Therefore, uncertainty remains as to the long-term consequences of Brexit

•

The Canadian economy is heavily dependent on relationships with certain key trading partners, including the U.S. and China. The Canadian economy is sensitive to fluctuations in certain commodity markets.

•

International trade is a large component of the Swiss economy and Switzerland depends upon exports to generate economic growth. The Swiss economy relies on certain key trading partners including the United States, Europe and China. Switzerland’s economic growth is generally correlated to slowdowns and growth trends experienced in other countries, including the U.S. and certain Western European countries.

•

Liquidity Risk. Liquidity risk exists when particular investments are difficult to purchase or sell. When the Fund holds these types of investments, the Fund’s portfolio may be more difficult to value, especially during periods of market turmoil or due to adverse changes in the conditions of a particular issuer. Markets may become illiquid when there are few, if any, interested buyers or sellers or when dealers are unwilling or unable to make a market for certain securities. As a general matter, dealers recently have been less willing to make markets for fixed income securities or when dealer market-making capacity is otherwise reduced. During times of market turmoil, there have been, and may be, no buyers for securities in entire asset classes, including U.S. Treasury securities. When the Fund holds illiquid investments, the Fund may be harder to value, especially in changing markets. Investments by the Fund in below investment grade securities, foreign securities, and corporate loans tend to involve greater liquidity risk. If the Fund is forced to sell or unwind these investments to meet redemptions or for other cash needs or try to limit losses, the Fund may suffer a substantial loss or may not be able to sell at all. Additionally, the market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and the difficulty in purchasing and selling such securities, may be unable to achieve its desired level of exposure to certain sectors. Further, certain securities, once sold, may not settle for an extended period. The Fund will not receive its sales proceeds until that time, which may constrain the Fund’s ability to meet its obligations (including obligations to redeeming shareholders).

Index Fund Risk. The Fund will invest in the stocks composing the World ex USA SRI ex Fossil Fuels Index regardless of how the Index is performing. It will not shift concentration from one industry to another, or from stocks to bonds or cash, in order to defend against a falling stock market. The Index may, at times, become focused in stocks of a particular sector, category or group of companies. Because the Fund seeks to track the World ex USA SRI ex Fossil Fuels Index, the Fund may underperform the overall stock market.

Non-Correlation Risk. The performance of the Fund and of the World ex USA SRI ex Fossil Fuels Index may vary for a variety of reasons. For example, the Fund incurs operating expenses and portfolio transaction costs not incurred by the Index. In addition, the Fund may not be fully invested in the component securities of the Index.

Valuation Risk. Nearly all of the Fund’s securities are valued using a fair value methodology. The sales price the Fund could receive for any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets. These differences may increase significantly and affect Fund investments more broadly during periods of market volatility. Investors who purchase or redeem Fund shares may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the Fund had not fair-valued securities or had used a different valuation methodology. The Fund’s ability to value its investments may be impacted by technological issues and/or errors by pricing services or other third party service providers.

their holdings in the Fund could hurt performance and/or cause the remaining shareholders in the Fund to lose money. Further, if one decision maker has control of Fund shares owned by separate Fund shareholders, including clients or affiliates of the Fund’s Adviser, redemptions by these shareholders may further increase the Fund’s redemption risk. If the Fund is forced to liquidate its assets under unfavorable conditions or at inopportune times, the value of your investment could decline.

Performance

The Fund’s past performance (before and after taxes) does not necessarily indicate how well it will perform in the future. Updated performance information is available on the Fund’s website, www.greencentury.com/fund-performance/, or by calling 1‑800‑934‑7336.

Annual Total Return for the Year Ended December 31

During the period shown, the best quarterly performance of the Fund’s Individual Investor Class was 15.68%, for the quarter ended 6/30/20. The worst quarterly performance of the Fund’s Individual Investor Class was -19.51%, for the quarter ended 3/31/20.

As of September 30, 2022, the year‑to‑date return for the Fund’s Individual Investor Class was -32.45%.

Average Annual Total Returns for the Periods Ended December 31, 2021



	1 Year			5 Years			Since Inception (September 30, 2016)
Green Century MSCI International Index Fund – Individual Investor Class
Return before taxes		12.54	%		10.86	%		9.67	%

Return after taxes on distributions		11.77	%		10.42	%		9.24	%

Return after taxes on distributions and sale of Fund shares		7.97	%		8.57	%		7.61	%
Green Century MSCI International Index Fund – Institutional Class
Return before taxes		12.90	%		11.19	%		9.98	%

MSCI World Ex USA Index (reflects no deduction for fees, expenses or taxes)		12.62	%		9.63	%		9.07	%

The after-tax returns are shown for the Individual Investor Class of the Fund and the after-tax returns for the Institutional Class of the Fund will vary. The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

Management

Investment Adviser: Green Century Capital Management, Inc.

Investment Subadviser: Northern Trust Investments, Inc. (NTI)

Portfolio Managers: Steven Santiccioli, Vice President of NTI, and Brent Reeder, Senior Vice President and Director of US Index Equities at NTI (portfolio managers since 2016) are jointly and primarily responsible for the day-to-day portfolio management of the Fund.

GREEN CENTURY FUNDS SUMMARY SECTION

Purchase and Sale of Fund Shares

You may purchase or redeem shares of a Fund by mail using one of the below addresses, online at www.greencentury.com/open-an-account/, by wire (instructions are available by calling 1‑800‑221‑5519), or through a financial intermediary. Investors who have signed up to do so may redeem shares in any account by calling 1-800-221-5519, and may redeem non-retirement account shares online at https://greencentury.access-my-account.com. If you invested through a financial intermediary, contact the intermediary for information on how to redeem shares. Additional investments may be made online by investors who have signed up for online services.



Mail new account registration forms, subsequent investments, redemption requests and other correspondence to:		For registered, certified or overnight mail, send to:
Green Century Funds P.O. Box 588 Portland, ME 04112		Green Century Funds c/o Apex Fund Services Three Canal Plaza, Ground Floor Portland, ME 04101

It is the Green Century Funds’ policy not to accept accounts that are an investment option of a government entity’s participant-directed plan or program, as defined in Rule 206(4)-5 of the Investment Advisors Act of 1940.

You may purchase or redeem shares of a Fund on any day the New York Stock Exchange is open.

Individual Investor Class: The minimum initial purchase amount for a regular investment account is $2,500 per Fund or $1,000 per Fund for investors who wish to open an account with a $100 or more per month Automatic Investment Plan. The minimum initial purchase is $1,000 per Fund for Traditional IRAs, Roth IRAs, SEP-IRAs, SIMPLE IRAs, Coverdell Education Savings Accounts, and Uniform Gifts or Transfers to Minors Accounts (UGMA/UTMA). The Funds reserve the right to waive minimums. Institutions as well as individuals may invest in the Individual Investor Class.

The minimum additional purchase amount is $100 by check, wire or exchange and $50 by either an Automatic Investment Plan or online.

Institutional Class: The minimum initial purchase amount is $250,000 per Fund. The Funds reserve the right to waive minimums. Individuals as well as institutions who invest $250,000 or more may invest in the Institutional Class.

The minimum additional purchase amount is $100 by check, wire or exchange and $50 by either an Automatic Investment Plan or online.

Tax Information

The Funds’ distributions are generally taxable as ordinary income, qualified dividend income, or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Such tax-advantaged arrangements may be taxed later upon withdrawal of monies from those accounts.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of a Fund through a broker/dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments create a conflict of interest by influencing the broker/dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s web site for more information.

ADDITIONAL INFORMATION ABOUT THE FUNDS’ INVESTMENT OBJECTIVES, STRATEGIES AND RISKS

Founded by a partnership of non-profit environmental and public health advocacy organizations. The Green Century Funds are an open-end, no-load family of mutual funds that seek to offer to people who care about a clean, healthy planet the opportunity to use the clout of their investment dollars to encourage environmentally responsible corporate behavior.

THE GREEN CENTURY BALANCED FUND

The Green Century Balanced Fund’s investment objective is to provide capital growth and income from a diversified portfolio of stocks and bonds which meet the Fund’s standards for corporate environmental responsibility.

The Fund invests primarily in the stocks and bonds U.S. companies that the Fund’s Adviser, Green Century Capital Management, believes are environmentally responsible and sustainable. Green Century defines its standard for environmentally responsible and sustainable as seeking to provide an opportunity to invest in a way that avoids environmentally dangerous industries which impose onerous costs on society and the planet. There is no predetermined percentage of assets allocated to either stocks or bonds, although the Fund will generally invest at least 25% of its net assets in bonds and may not invest more than 75% of its net assets in stocks.

The Balanced Fund’s Subadviser’s equity investment process includes: a quality-driven research process through which ideas are generated for creating the Fund’s portfolio, including a thorough analysis and review of recommendations for the Fund’s portfolio, and a portfolio construction process led by the insights of the Fund’s portfolio managers that includes a macroeconomic input and a review of adherence to risk control parameters.

The Subadviser’s fundamental equity analysts divide coverage by sector and are responsible for providing in-depth analysis of companies and generating new buy ideas consistent with the Subadviser’s belief in investing in high quality companies. The Subadviser conducts a financial and business model review, evaluating characteristics such as:

•

Financial Returns on Investment

•

Business Strategy Strength

•

Growth and Earnings Quality

•

Profitability and Efficiency

•

Financial Leverage

The Subadviser seeks to identify companies that it believes are strategic leaders, based on business models that it thinks are superior and demonstrate the ability to create consistent earnings growth.

Once the Subadviser’s analysts determine specific potential investments that look promising for further research, the analysts begin an in-depth fundamental research process that includes full integration of ESG issues that are most material to a particular industry, based on the Subadviser’s assessment that the issues have both high stakeholder concern and financial risk.

In constructing the Fund’s portfolio, the portfolio managers adhere to specific risk control parameters. A key step in the portfolio construction process is sector allocation which is informed by evaluating the current macroeconomic environment, developing cycles, and trends, based on among other factors the strategy cycle, valuation, and structural factors. The Balanced Fund’s portfolio managers integrate the findings of the macroeconomic review into each portfolio rebalancing process. The resulting sector allocation for the equity component of the Balanced Fund is based on an integration of this top-down view with the bottom-up assessment of opportunity at the stock level.

The Subadviser monitors the companies in the Balanced Fund’s portfolio to determine if there have been any fundamental changes in the companies or changes in the companies’ environmental records and policies. The Subadviser also regularly analyzes quantitative measures such as price/earnings ratios, price/cash flow ratios and other quantitative measures to monitor stock price movements and help determine whether to sell a stock in the Fund’s portfolio. The Subadviser may sell a stock if, among other factors:

•

It subsequently fails to meet the Fund’s investment criteria or becomes overvalued relative to the long-term expectation for its stock price;

•

The balance between the stock’s expected return and its contribution to the risk of the portfolio deteriorates or a more attractively priced company is identified;

•

Changes in national economic conditions, such as interest rates, unemployment, and productivity levels, prompt a change in industry sector allocation for the Fund’s portfolio;

•

The company’s environmentally responsible and sustainable practices, as identified by Green Century or the Subadviser, no longer avoids investing in environmentally dangerous industries and dialogue and shareholder engagement fails to change the company’s policies.

The Balanced Fund may maintain a de minimis position in a stock following the Subadviser’s decision to sell the holding when Green Century is advocating for improved corporate environmental policies at the company.

The bonds the Fund invests in may be of any maturity and are generally of investment grade quality. In general, fixed income securities are included in the Fund’s portfolio to balance or offset risks associated with the Fund’s investment in stocks. Fixed income investments are evaluated using the same environmental criteria as those employed for equity investments. Issuer-specific financial evaluation of fixed income investments focuses on an issuer’s cash flow, interest rate coverage, and other measures of its ability to meet its future income and principal repayment commitments. In addition, each fixed income investment is evaluated with respect to its credit quality and its overall exposure to interest rate risk.

The Balanced Fund’s assets may be invested in: domestic and foreign securities, including common stock, preferred stock and other equity securities, exchange traded funds, bonds and other fixed income securities, Certificates of Deposit, promissory notes, floating rate obligations, and money market instruments, in each case, compatible with the Fund’s commitment to environmental responsibility. The other fixed income securities in which the Fund may invest include: U.S. Government securities, securities issued by supra‑ national or foreign domiciled entities, municipal securities, mortgage-backed securities, asset-backed securities, and zero coupon securities. The Fund may also engage in writing and purchasing options on portfolio securities. The Fund may, but is not required to, utilize derivatives, such as equity index and bond

futures, in an effort to reduce risk or increase market exposure, but not to create exposure greater than the value of underlying assets held in the Fund. There is no predetermined percentage of assets allocated to either stocks or bonds, although the Balanced Fund will generally invest at least 25% of its net assets in fixed income securities (bonds). The Fund may not invest more than 75% of its net assets in equity securities (stocks). For temporary defensive purposes, the Fund may invest up to 100% of its assets in cash and other money market and short-term instruments. Any such temporary defensive investing will also comply with the Fund’s environmental criteria. The effect of taking such a position is that the Fund may not achieve its investment objective.

Zero Coupon Securities. The Balanced Fund may invest in zero coupon securities which do not make regular interest payments; rather, they are sold at a discount from face value. Principal and accrued discount (representing interest accrued but not paid) are paid at maturity. Zero coupon securities are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities which make current cash distributions of interest. Zero coupon securities are more likely to respond to changes in interest rates than other securities that have similar maturities and credit quality, and are more sensitive to the credit quality of the underlying issuer. Unlike bonds that pay interest throughout the period to maturity, the Fund generally will realize no cash from a zero coupon security until maturity and, if the issuer defaults, the Fund may obtain no return at all on its investment. In order to pay cash distributions representing income on zero coupon securities, the Fund may have to sell other securities on unfavorable terms. These sales may generate taxable gains for shareholders.

High Yield Debt Securities. The Balanced Fund may invest up to 35% of its net assets in high yield, below investment grade bonds, commonly known as junk bonds. Below investment grade securities are securities that, at the time of the investment, are either rated below Baa by a nationally recognized securities rating organization or, if not rated, considered to be of equivalent quality by the Subadviser of the Balanced Fund. The Statement of Additional Information provides a description of bond rating categories. Trillium, the Subadviser to the Balanced Fund, intends to, but is not required to, limit the proportion of below investment grade securities to no more than 15% of the Fund’s net assets. As of July 31, 2022, the Fund had no investments in below investment grade securities.

While these securities generally offer higher yields than investment grade securities with similar maturities, lower-quality securities involve greater risks, including the possibility of default or bankruptcy. Generally, they are considered to be predominantly speculative regarding, and more dependent on, the issuer’s ability to pay interest and repay principal. Such inability (or perceived inability) would likely lessen the value of such securities, which could lower the Fund’s net asset value per share. Issuers of high-yield securities may not be as strong financially as those issuing bonds with higher credit ratings. Other potential risks associated with investing in high-yield securities include: heightened sensitivity of highly-leveraged issuers to adverse economic changes and individual-issuer developments; subordination to the prior claims of other creditors; adverse publicity and changing investor perceptions about these securities; and generally less liquid markets. The Fund may incur additional expenses to the extent that it is required to seek recovery upon a default in the payment of principal and interest on its holdings. A holder of securities that are subordinated or “junior” to more senior securities of an issuer is entitled to payment after holders of more senior securities of the issuer. As a result, subordinated securities will be disproportionately adversely affected by a default or even a perceived decline in creditworthiness of the issuer, or, in the case of a pooled investment,

issuers of underlying obligations. Because of the associated risks, successful investments in high-yield, high- risk securities are more dependent on the Subadviser’s credit analysis than generally would be the case with investments in investment grade securities.

U.S. Government Securities. The Balanced Fund may invest in U.S. government securities. U.S. government securities include obligations: directly issued by or supported by the full faith and credit of the U.S. government, like Treasury bills, notes and bonds and Government National Mortgage Association certificates; supported by the right of the issuer to borrow from the U.S. Treasury, like those of the Federal Home Loan Banks; supported by the discretionary authority of the U.S. government to purchase the agency’s securities like those of the Federal National Mortgage Association; or supported only by the credit of the issuer itself, like the Tennessee Valley Authority. The U.S. government has provided financial support to the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation in the past, but there can be no assurance that it will support these or other government-sponsored enterprises in the future.

Municipal Securities. The Balanced Fund may invest in municipal securities. Municipal securities include debt obligations issued by any of the 50 U.S. states and the District of Columbia or their political subdivisions, agencies and public authorities, certain other U.S. governmental issuers (such as Puerto Rico, the U.S. Virgin Islands and Guam) and other qualifying issuers, participation or other interests in these securities and other structured securities. Although municipal securities are issued by qualifying issuers, payments of principal and interest on municipal securities may be derived solely from revenues from certain facilities, mortgages or private industries, and may not be backed by the issuers themselves. These securities include participation or other interests in municipal securities issued or backed by banks, insurance companies and other financial institutions.

Municipal Securities Risk. The municipal bond marketcan be susceptible to unusual volatility, particularly for lower-rated and unrated securities. Liquidity can be reduced unpredictably in response to overall economic conditions or credit tightening. Municipal issuers may be adversely affected by rising health care costs, increasing unfunded pension liabilities, and by the phasing out of federal programs providing financial support. Unfavorable conditions and developments relating to projects financed with municipal securities can result in lower revenues to issuers of municipal securities, potentially resulting in defaults. Issuers often depend on revenues from those projects to make principal and interest payments. The value of municipal securities can also be adversely affected by changes in the financial condition of one or more individual municipal issuers or insurers of municipal issuers, regulatory and political developments, tax law changes or other legislative actions, and by uncertainties and public perceptions concerning these and other factors. Municipal issuers may be more susceptible to downgrades or defaults during recessions or similar periods of economic stress. Financial difficulties of municipal issuers may continue or worsen particularly in the event of economic or market turmoil or a recessions.

Mortgage-Backed Securities. The Balanced Fund may invest in mortgage-backed or mortgage-related securities. Mortgage-related securities may be issued by private companies or by agencies of the U.S. government and represent direct or indirect participation in, or are collateralized by and payable from, mortgage loans secured by real property. Unlike mortgage-related securities issued or guaranteed by the U.S. government or its agencies and instrumentalities, mortgage-related securities issued by private issuers

do not have a government or government-sponsored entity guarantee (but may have other credit enhancement), and may, and frequently do, have less favorable collateral, credit risk or other underwriting characteristics.

Risks of Mortgage-Backed Securities. Mortgage-related securities are subject to special risks. The repayment of certain mortgage-related securities depends primarily on the cash collections received from the issuer’s underlying asset portfolio and, in certain cases, the issuer’s ability to issue replacement securities (such as asset-backed commercial paper). As a result, there could be losses to the Balanced Fund in the event of credit or market value deterioration in the issuer’s underlying portfolio, mismatches in the timing of the cash flows of the underlying asset interests and the repayment obligations of maturing securities, or the issuer’s inability to issue new or replacement securities. This is also true for other asset-backed securities. Upon the occurrence of certain triggering events or defaults, the Balanced Fund may become the holder of underlying assets at a time when those assets may be difficult to sell or may be sold only at a loss. In the event of a default, the value of the underlying collateral may be insufficient to pay certain expenses, such as litigation and foreclosure expenses, and inadequate to pay any principal or unpaid interest. The risk of default is generally higher in the case of mortgage-backed investments offered by private issuers and those that include so-called “sub-prime” mortgages. Privately issued mortgage-backed and asset-backed securities are not traded on an exchange and may have a limited market. Without an active trading market, these securities may be particularly difficult to value given the complexities in valuing the underlying collateral. Certain debt instruments may pay principal only at maturity or may represent only the right to receive payments of principal or interest on the underlying obligations, but not both. The value of these types of instruments may change more drastically than debt securities that pay both principal and interest during periods of changing interest rates. Principal only instruments generally increase in value if interest rates decline, but are also subject to the risk of prepayment. Interest only instruments generally increase in value in a rising interest rate environment when fewer of the underlying obligations are prepaid, but remain subject to prepayment risk, which would be a loss of any expected interest payments, even though there is no default on the underlying financial asset.

Derivatives. The Balanced Fund may, but is not required to, utilize derivatives, such as equity index and bond futures. Using derivatives such as futures can increase Fund losses and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the Fund. Using derivatives also can have a leveraging effect and increase fund volatility. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the Fund. Many over-the-counter derivative instruments will not have liquidity beyond the counterparty to the instrument. Use of derivatives or similar instruments may have different tax consequences for the Fund than an investment in the underlying security, and those differences may affect the amount, timing and character of income distributed to shareholders. The Fund’s use of derivatives may also increase the amount of taxes payable by shareholders. Derivatives may not be available on terms that make economic sense (for example, they may be too costly). Risks associated with the use of derivatives are magnified to the extent that a large portion of the Fund’s assets are committed to derivatives in general or are invested in just one or a few types of derivatives. The U.S. government and foreign governments are in the process of adopting and implementing regulations governing derivative markets, including mandatory clearing of certain derivatives, margin, and reporting requirements. The ultimate impact of the regulations remains unclear.

Additional regulations may make using derivatives costlier, may limit their availability or utility or otherwise adversely affect their performance or may disrupt markets. The Fund may be exposed to additional risks as a result of the additional regulations. The extent and impact of the additional regulations are not yet fully known and may not be for some time. The Fund may choose not to make use of derivatives for a variety of reasons, and any use may be limited by applicable law and regulations.

THE GREEN CENTURY EQUITY FUND

The Green Century Equity Fund’s investment objective is to achieve long-term total return which matches the performance of an index of the stocks of companies selected based on environmental, social and corporate governance criteria.

The Equity Fund invests substantially all of its assets in the common stocks comprising the KLD400 ex Fossil Fuels Index, a custom index calculated by MSCI Inc. The KLD400 ex Fossil Fuels Index is comprised of the common stocks of the approximately 400 companies in the MSCI KLD 400 Social Index (the KLD400 Index), minus the stocks of the companies that explore for, extract, produce, manufacture or refine coal, oil or gas or produce or transmit electricity derived from fossil fuels or transmit natural gas or have carbon reserves included in the KLD400 Index. Companies included in the KLD400 Index are identified based on a review of ESG ratings; the KLD400 Index is composed of companies with what MSCI calculates to have high ESG ratings.

MSCI ESG Research analyzes a company’s commitment to sustainability across the following ESG issues that focus on the intersection between a company’s core business and the industry-specific issues that may create significant risks and opportunities for the company:

•

Environmental issues, including:

Climate Change: carbon emissions; product carbon footprint; financing environmental impact; and climate change vulnerability.

Natural Capital: water stress; biodiversity and land use; and raw material sourcing.

Pollution and Waste: toxic emissions and waste; packaging material and waste; and electronic waste.

Environmental Opportunities: clean technology; green building; and renewable energy.

•

Social issues, including:

Human Capital: labor management; health and safety; human capital development; and supply chain labor standards.

Product Liability: product safety and quality; chemical safety; financial product safety; privacy and data security; responsible investment; and insuring health and demographic risk.

Stakeholder Opposition: controversial sourcing.

Social Opportunities: access to communication; access to finance; access to health care; and opportunities in nutrition and health.

•

Governance issues, including:

Corporate Governance: board; pay; ownership and accounting.

Corporate Behavior: business ethics; anti-competitive practices; corruption and instability; financial system instability; and tax transparency.

Companies that MSCI ESG Research has determined to have significant business involvement in the following will not be included in the KLD400 Index:

•

Companies that are primarily engaged in the manufacture of tobacco products, which are linked to air pollution, deforestation, and plastic pollution, as well as health problems.

•

Companies that have a significant business involvement in genetically modified organisms (GMOs) whose use has led to increased use of toxic herbicides.

•

Companies that are in industries that produce firearms or military weapons.

•

Companies that are primarily engaged in gambling, alcohol or adult entertainment.

The KLD400 Index also seeks to maintain broad sector representation. The weightings of the stocks comprising the KLD400 Index are based upon float-adjusted market capitalization. The composition of the KLD400 Index is reviewed on a regular quarterly basis, following which companies can be added to the KLD400 Index. During the quarterly reviews, companies are evaluated to determine if any should be removed from the KLD400 Index due to deteriorated environmental, social or governance performance or due to removal from the applicable MSCI universe. Deleted companies are replaced with eligible companies and the KLD400 Index will be restored to 400 companies following each quarterly review. As of each quarterly restoration of the KLD400 Index, MSCI ESG Research will remove the companies in the KLD400 Index that explore for, extract, produce, manufacture or refine coal, oil or gas or produce or transmit electricity derived from fossil fuels or transmit natural gas or have carbon reserves to create the KLD400 ex Fossil Fuels Index. The criteria used in developing and maintaining both the KLD400 Index and the KLD400 ex Fossil Fuels Index involve subjective judgment by MSCI. The Equity Fund is not managed in the traditional investment sense, since changes in the composition of its securities holdings are made in order to track the changes in the composition of securities included in the KLD400 ex Fossil Fuels Index.

The Equity Fund may invest cash reserves in high quality short-term debt securities issued by agencies or instrumentalities of the United States Government, bankers’ acceptances, commercial paper, certificates of deposit, bank deposits or repurchase agreements provided that the issuer satisfies Green Century’s social criteria. The Equity Fund’s policy is to hold its assets in such securities pending readjustment of its holdings of stocks comprising the KLD400 ex Fossil Fuels Index and in order to meet anticipated redemption requests. The Equity Fund may also invest in such securities for temporary defensive purposes. This may adversely affect the Equity Fund’s performance.

The Equity Fund buys and sells stocks periodically so that its holdings will correspond, to the extent reasonably practicable, to the KLD400 ex Fossil Fuels Index. The timing and extent of adjustments in the holdings of the Equity Fund, and the extent of the correlation of the holdings of the Equity Fund with the KLD400 ex Fossil Fuels Index, reflects the judgment of the Equity Fund’s Subadviser as to the appropriate

balance between the goal of correlating the holdings of the Equity Fund with the composition of the KLD400 ex Fossil Fuels Index, and the goals of minimizing transaction costs and keeping sufficient reserves available for anticipated redemptions from the Equity Fund. To the extent practicable, the Equity Fund will seek a correlation between the weightings of securities held by the Equity Fund and the weightings of the securities in the KLD400 ex Fossil Fuels Index of 0.95 or better. A figure of 1.00 would indicate a perfect correlation. The Equity Fund’s ability to duplicate the performance of the KLD400 ex Fossil Fuels Index will depend to some extent on the size and timing of cash flows into and out of the Equity Fund as well as the Equity Fund’s expenses.

Under normal circumstances and as a matter of operating policy, the Fund will invest at least 80% of its assets in equity securities and related investments. The Fund will provide shareholders with at least 60 days’ notice of any change to its 80% investment policy.

THE GREEN CENTURY INTERNATIONAL INDEX FUND

The Green Century International Index Fund’s investment objective is to achieve long-term total return which matches the performance of an index of the stocks of foreign companies selected based on environmental, social and corporate governance criteria.

The International Index Fund invests substantially all of its assets in the common stocks which make up the World ex USA SRI ex Fossil Fuels Index, a custom index calculated by MSCI Inc. The World ex USA SRI ex Fossil Fuels Index is comprised of the common stocks of the companies in the MSCI World ex USA SRI Index (the World ex USA SRI Index), minus the stocks of the companies that explore for, extract, produce, manufacture or refine coal, oil or gas or produce or transmit electricity derived from fossil fuels or transmit natural gas or have carbon reserves included in the World ex USA SRI Index. The World ex USA SRI Index includes large and mid-cap stocks from approximately 22 developed markets countries (excluding the U.S.). The World ex USA SRI Index is a capitalization weighted index that provides exposure to companies with what MSCI calculates to have high ESG ratings. The World ex USA SRI ex Fossil Fuels Index is a capped version of the World ex USA SRI Index that limits company concentration by constraining the maximum weight of a company to 5% of the index.

•

Environmental issues, including:

Climate Change: carbon emissions; product carbon footprint; financing environmental impact; and climate change vulnerability.

Natural Capital: water stress; biodiversity and land use; and raw material sourcing.

Pollution and Waste: toxic emissions and waste; packaging material and waste; and electronic waste.

Environmental Opportunities: clean technology; green building; and renewable energy.

•

Social issues, including:

Human Capital: labor management; health and safety; human capital development; and supply chain labor standards.

Product Liability: product safety and quality; chemical safety; financial product safety; privacy and data security; responsible investment; and insuring health and demographic risk.

Stakeholder Opposition: controversial sourcing.

Social Opportunities: access to communication; access to finance; access to health care; and opportunities in nutrition and health.

•

Governance issues, including:

Corporate Governance: board; pay; ownership and accounting.

Corporate Behavior: business ethics; anti-competitive practices; corruption and instability; financial system instability; and tax transparency.

Companies that MSCI ESG Research has determined to have significant business involvement in the following will not be included in the World ex USA SRI Index:

•

Companies that are primarily engaged in the manufacture of tobacco products, which are linked to air pollution, deforestation, and plastic pollution, as well as health problems.

•

Companies that have a significant business involvement in genetically modified organisms (GMOs) whose use has led to increased use of toxic herbicides.

•

Companies that are in industries that produce firearms or military weapons.

•

Companies that are primarily engaged in gambling, alcohol or adult entertainment.

The World ex USA SRI Index also seeks to maintain broad sector representation. The weightings of the stocks comprising the World ex USA SRI Index are based upon float-adjusted market capitalization. The composition of the World ex USA SRI Index is reviewed on a regular basis in May and rebalanced in May, August, November and February. During the reviews, the companies that comprise the World ex USA SRI Index are evaluated to determine if any should be removed due to deteriorated environmental, social or governance performance. Existing constituents that do meet the eligibility criteria are retained in the World ex USA SRI Index. The criteria used in developing and maintaining both the World ex USA SRI Index and the World ex USA SRI ex Fossil Fuels Index involve subjective judgment by MSCI. The International Index Fund is not managed in the traditional investment sense, since changes in the composition of its securities holdings are made in order to track the changes in the composition of securities included in the World ex USA SRI ex Fossil Fuels Index.

The MSCI Global SRI Indexes, including the World ex USA SRI Index, are constructed by applying a combination of values based exclusions and a Best in Sector selection process to companies in the regional indexes that make up MSCI ACWI (All Country World Index), a global equity index consisting of developed and emerging market countries. After securities involved in GMOs, firearms, military weapons, nuclear power, alcohol, tobacco, adult entertainment and gambling are excluded, MSCI’s Best in Sector selection

process is applied to the remaining eligible securities in the selection universe. The MSCI Global SRI Indexes target sector and region weights consistent with those of the underlying indexes. The methodology aims to include the securities of companies with the highest ESG ratings making up 25% of the market capitalization in each sector and region of the parent indexes. The selection universe for the MSCI Global SRI Indexes is the constituents of the MSCI Global Investable Market Indexes.

The International Index Fund may invest cash reserves in high quality short-term debt securities issued by agencies or instrumentalities of the United States Government, bankers’ acceptances, commercial paper, certificates of deposit, bank deposits or repurchase agreements provided that the issuer satisfies Green Century’s ESG criteria. The International Index Fund’s policy is to hold its assets in such securities pending readjustment of its holdings of stocks comprising the World ex USA SRI ex Fossil Fuels Index and in order to meet anticipated redemption requests. The International Index Fund may also invest in such securities for temporary defensive purposes. This may adversely affect the International Index Fund’s performance.

The International Index Fund buys and sells stocks periodically so that its holdings will correspond, to the extent reasonably practicable, to the World ex USA SRI ex Fossil Fuels Index. The timing and extent of adjustments in the holdings of the International Index Fund, and the extent of the correlation of the holdings of the International Index Fund with the World ex USA SRI ex Fossil Fuels Index, reflects the judgment of the International Index Fund’s Subadviser as to the appropriate balance between the goal of correlating the holdings of the International Index Fund with the composition of the World ex USA SRI ex Fossil Fuels Index, and the goals of minimizing transaction costs and keeping sufficient reserves available for anticipated redemptions from the International Index Fund. To the extent practicable, the International Index Fund will seek a correlation between the weightings of securities held by the International Index Fund and the weightings of the securities in the World ex USA SRI ex Fossil Fuels Index of 0.95 or better. A figure of 1.00 would indicate a perfect correlation. The International Index Fund’s ability to duplicate the performance of the World ex USA SRI ex Fossil Fuels Index will depend to some extent on the size and timing of cash flows into and out of the International Index Fund as well as the International Index Fund’s expenses.

THE GREEN CENTURY FUNDS

Foreign Securities. While each of the Balanced Fund and the Equity Fund emphasizes investment in U.S. companies, they may also invest in foreign securities. The Balanced Fund may invest up to 30% of its assets in foreign securities of the same types as the domestic securities in which the Fund may invest. The Funds may also invest in American Depositary Receipts (ADRs) and the Balanced Fund may invest in Global Depositary Receipts (GDRs) with respect to such foreign securities. The Balanced Fund may also invest in certificates of deposit issued by foreign banks, foreign and domestic branches of U.S. banks, obligations issued or guaranteed by foreign governments or political subdivisions thereof, obligations issued by supra-national organizations, and corporate bonds denominated in dollars but issued by foreign companies.

The International Index Fund invests substantially all its assets in foreign securities. The Fund may also invest in American Depositary Receipts (ADRs), in Global Depositary Receipts (GDRs) and Euro Depository Receipts with respect to such foreign securities.

Foreign securities involve some special risks, such as exposure to potentially adverse local political and economic developments; nationalization and exchange controls; potentially lower liquidity and higher volatility; possible problems arising from accounting, disclosure, settlement, and regulatory practices that differ from U.S. standards; and the chance that fluctuations in foreign exchange rates will decrease the investment’s value (favorable changes can increase its value). Foreign investments must be made in compliance with U.S. and foreign currency restrictions and laws restricting the amounts and types of foreign investments.

Portfolio Turnover. Purchases and sales are made for a portfolio whenever necessary, in management’s opinion, to meet its investment objective. Higher levels of activity result in higher transaction costs and may also result in higher taxable capital gains distributions to shareholders. The Balanced Fund’s portfolio turnover rate for the fiscal years ended July 31, 2020, 2021 and 2022 were 25%, 17% and 9%, respectively.

Frequent changes in the Equity Fund’s holdings may result from the policy of attempting to correlate the Equity Fund’s securities holdings with the composition of the KLD400 ex Fossil Fuels Index. The portfolio turnover rate of the Equity Fund for the fiscal years ended July 31, 2020, 2021 and 2022 were 10%, 9% and 5%, respectively.

Frequent changes in the International Index Fund’s holdings may result from the policy of attempting to correlate the International Index Fund’s securities holdings with the composition of the World ex USA SRI ex Fossil Fuels Index. The portfolio turnover rate of the of the International Index Fund for the fiscal years ended July 31, 2020, 2021 and 2022 were 20%, 31% and 29%, respectively.

Investment Restrictions. None of the Funds intends to concentrate its investments (i.e. invest more than 25% of its assets) in a particular industry. However, because the Equity Fund and the International Index Fund each generally invests substantially all its assets in the component securities of the KLD400 ex Fossil Fuels Index and the World ex USA ex Fossil Fuels Index, respectively, if stocks in a single industry comprise more than 25% of an Index, the Equity Fund and the International Index Fund will invest more than 25% of its assets in that industry. If the Equity Fund or the International Index Fund were to concentrate its investments in a single industry, the Equity Fund or the International Index Fund would be more susceptible to risks associated with that industry than would a fund which was not so concentrated.

The investment objectives of the Balanced Fund, the Equity Fund and the International Index Fund are not fundamental and may be changed without the approval of shareholders if written notice is provided to shareholders prior to implementing the change. Because of the risks inherent in all investments, there can be no assurance that the objectives of the Funds will be met. Except as stated otherwise, all investment guidelines, policies and restrictions described here and in the Statement of Additional Information are non- fundamental.

Portfolio Holdings Disclosure. The Funds have adopted policies and procedures which govern the timing and circumstances of disclosure to shareholders and third parties of information regarding the portfolio investments held by each of the Funds. The Policies and Procedures for the Disclosure of the Green Century Funds’ Portfolio Holdings is included in the Statement of Additional Information.

ENVIRONMENTALLY RESPONSIBLE INVESTING

Green Century Capital Management’s mission is to promote corporate environmental responsibility and to foster a sustainable economy. The three-prong strategy to achieve these goals:

•

Sponsor mutual funds which strive to avoid environmentally dangerous companies and invest in environmentally responsible and sustainable companies.

•

Advocate for more environmentally responsible policies and practices at major corporations

•

Support the non-profit public interest and advocacy organizations that founded Green Century

THE GREEN CENTURY FUNDS’ ENVIRONMENTAL STANDARDS

Environmentally responsible investing is investing based on your financial goals and your environmental values. While each Green Century Fund shares a commitment to environmental responsibility, each Fund employs a different strategy. This section is dedicated to describing Green Century’s environmentally responsible investment strategies.

The Green Century Balanced Fund seeks to promote environmentally responsible corporate behavior and a cleaner environment by investing in companies that the Fund’s Adviser, Green Century Capital Management, believes are environmentally responsible and sustainable. Such companies include, but are not limited to, those that demonstrate a commitment to preserving and enhancing the environment as evidenced by the products they make and the services they provide and those companies that make positive contributions toward actively promoting a healthier environment and a sustainable future.

For both environmental and financial reasons, Green Century applies rigorous selection criteria concerning the environmental behavior of the companies in which the Fund invests. Green Century believes that well- managed environmentally responsible companies minimize their environmental risks, which may allow them to enjoy competitive advantages from cost reductions, quality improvements, profitability enhancements and access to expanding and new growth markets. Further, Green Century believes that companies that are responsible towards the environment are more likely to act ethically and maintain the trust of their shareholders.

The Balanced Fund seeks to invest in companies that Green Century believes conduct their business in an environmentally responsible and sustainable manner. Such companies include those whose primary business involves the provision of what Green Century believes are environmentally sound goods or services, such as appropriate technology for sustainable agriculture, renewable energy, energy efficiency, water treatment and conservation, air pollution control, pollution prevention, recycling technologies, or other effective remedies for existing environmental problems. The Fund also invests in companies whose primary business is not solving environmental problems but which seek to conduct their business in what

Green Century believes is an environmentally responsible manner. Such companies are evaluated on a range of criteria that may include, but is not necessarily limited to, an assessment of each company’s:

•

Environmental performance indicators such as its consumption of natural resources, energy usage, greenhouse gas emissions, toxic emissions, use of toxic chemicals, and solid waste generation

•

Pollution prevention programs and supply chain environmental policies

•

Compliance with environmental laws and regulations and its potential environmental liabilities

•

Environmental management infrastructure and governance procedures

•

Public reporting on an annual basis of its environmental performance

The Balanced Fund does not intend to invest in companies that primarily explore for, extract, produce, manufacture or refine coal, oil or gas or produce or transmit electricity derived from fossil fuels or transmit natural gas or have material carbon reserves; the Fund may invest in companies that use fossil fuel-based energy to power their operations or for other purposes.

Green Century believes that certain industries impose onerous costs on society and the planet; thus at various times the Balanced Fund may not be invested in any companies in industries Green Century believes threaten a sustainable global environment. The Fund does not intend to invest in companies that have a significant business involvement in the following: genetically modified organisms (GMOs), firearms, military weapons, factory farms, nuclear power or tobacco.

The Green Century Equity Fund invests in the stocks of the companies included in the KLD400 ex Fossil Fuels Index, which is comprised of the approximately 400 companies of the KLD400 Index minus the companies that explore for, extract, produce, manufacture or refine coal, oil or gas or produce or transmit electricity derived from fossil fuels or transmit natural gas or have carbon reserves. Companies included in the KLD400 Index are identified based on a review of ESG ratings; the KLD400 Index is composed of companies with what MSCI calculates to have high ESG ratings. Green Century also believes that constructing a Fund’s portfolio based on ESG criteria creates an incentive for companies to become more sustainable and to become better corporate citizens.

Green Century also believes that those companies which seek to manage their ESG risks may be better prepared to avoid reputational, competitive, regulatory and material risks and may benefit financially as a result.

In constructing the Fund’s KLD400 Index, MSCI ESG Research analyzes a company’s commitment to sustainability across ESG issues that focus on the intersection between a company’s core business and the industry-specific issues that may create significant risks and opportunities for the company, as discussed above.

The International Index Fund invests in the stocks of the companies included in the World ex USA SRI ex Fossil Fuels Index, which is comprised of the companies of the World ex USA SRI Index minus the companies that explore for, extract, produce, manufacture or refine coal, oil or gas or produce or transmit electricity derived from fossil fuels or transmit natural gas or have carbon reserves. The World ex USA SRI Index is a capitalization weighted index that provides exposure to companies with what MSCI calculates to have high ESG ratings. Green Century also believes that constructing a Fund’s portfolio based on ESG criteria creates an incentive for companies to become more sustainable and to become better corporate citizens.

Green Century also believes that those companies which seek to manage their environmental, social and governance risks may be better prepared to avoid reputational, competitive, regulatory and material risks and may benefit financially as a result.

In constructing the World ex USA SRI ex Fossil Fuels Index, MSCI ESG Research analyzes a company’s commitment to sustainability across ESG issues that focus on the intersection between a company’s core business and the industry-specific issues that may create significant risks and opportunities for the company, as discussed above.

The Green Century Funds. The Green Century Funds usually invest in many sectors of the economy, such as retail, finance, technology and consumer products. The Funds are not environmental sector funds which invest exclusively in companies whose business derives from environmental problems (such as waste-management or incinerator manufacturers), some of which have consistently negative environmental records.

ADVOCATES FOR CORPORATE ENVIRONMENTAL RESPONSIBILITY

The Green Century Funds believe that shareholder advocacy is a critical component of environmentally responsible investing and are actively involved in advocating for greater corporate environmental accountability.

Green Century Capital Management advocates for more environmentally responsible policies at the companies in which the Funds invest, as well as at companies in which none of the Funds has invested.

Green Century holds dialogues with companies and files shareholder resolutions in an effort to create positive environmental change. Green Century works to preserve and protect threatened ecosystems; advocate for more renewable energy and greenhouse gas emissions goals and reduce plastic pollution.

Green Century Capital Management is committed to pursuing demands for improved corporate environmental responsibility and to fostering a sustainable economy.

THE GREEN CENTURY FUNDS SUPPORT NOT-FOR-PROFIT ADVOCACY ORGANIZATIONS

The Green Century Funds were founded by non-profit environmental advocacy organizations. Unlike other investment advisers and administrators that are privately owned for the benefit of individuals or for-profit corporations, Green Century Capital Management is owned by Paradigm Partners, a California general partnership, the partners of which are all not-for-profit advocacy organizations. This means that 100% of the net profits earned by Green Century Capital Management on the fees it receives for managing the Funds belong to these not-for-profit advocacy organizations. These revenues will be used to support public interest campaigns, such as such as seeking to reduce the use of plastics, seeking to stop the use of dangerous pesticides, advocating for consumer’s right to repair products, seeking to reduce dangers to children’s health such as toxic chemicals and unsafe products, working for improved public transportation, advocating for public health protections, including the overuse of antibiotics, and championing consumer protection and corporate accountability.

The organizations which founded and own Green Century Capital Management are: California Public Interest Research Group (CALPIRG), Citizen Lobby of New Jersey (NJPIRG), Colorado Public Interest Research Group (COPIRG), ConnPIRG Citizen Lobby, Fund for the Public Interest, Massachusetts Public Interest Research Group (MASSPIRG), MOPIRG Citizen Organization, PIRGIM Public Interest Lobby, and Washington State Public Interest Research Group (WASHPIRG). Green Century is the only mutual fund company founded and owned by environmental non-profits, making it a pioneer in impact investing.

Green Century Capital Management may also provide grant and other funding to non-profit advocacy organizations to support their campaign work on wilderness protection, environmental protection, clean energy and other issues.

MANAGEMENT OF THE GREEN CENTURY FUNDS

THE GREEN CENTURY BALANCED FUND

Investment Adviser. Green Century Capital Management, 114 State Street, Suite 200, Boston, Massachusetts 02109, is the investment adviser for the Balanced Fund and oversees the portfolio management of the Balanced Fund on a day-to-day basis. Green Century Capital Management’s role is to ensure that the Balanced Fund’s investment objective and environmental and investment policies are accurately and effectively implemented. Green Century Capital Management has served as investment adviser and administrator for the Balanced Fund since the commencement of operations of the Balanced Fund.

Investment Subadviser. Trillium Asset Management LLC (Trillium), Two Financial Center, Boston, Massachusetts 02111, serves as the Subadviser for the Balanced Fund. Trillium is a wholly owned subsidiary of Perpetual US Holding Company, a subsidiary of Perpetual Limited. Perpetual Limited is a diversified financial services company that has been serving Australians since 1886. Trillium conducts the day-to-day investment management for the Fund consistent with the guidelines set by Green Century Capital Management. Trillium conducts fundamental security analysis that integrates ESG information.

Trillium has managed investments in environmentally and socially responsible companies since 1982. As of September 30, 2022, Trillium had approximately $4 billion in assets under management. Trillium is paid by the Adviser (not the Fund).

A team of three portfolio managers at Trillium are jointly responsible for the day-to-day portfolio management of the Balanced Fund. The team is comprised of Cheryl Smith, CFA, Ph.D.; Matthew Patsky, CFA; and Paul Hilton, CFA. Ms. Smith has been with Trillium for over 30 years; Mr. Patsky joined Trillium in 2009; and Mr. Hilton joined Trillium in 2011. Ms. Smith has served as a portfolio manager of the Balanced Fund since 2005. Mr. Patsky has served as a portfolio manager of the Balanced Fund since 2009. Mr. Hilton has served as a portfolio manager of the Balanced Fund since 2018. The Statement of Additional Information contains additional information about Ms. Smith, Mr. Patsky and Mr. Hilton, their compensation, other accounts they manage, and their ownership of shares of the Balanced Fund.

Discussions regarding the basis of the Board of Trustees’ approval of the continuance of the Balanced Fund’s Investment Advisory Agreement with Green Century Capital Management and Investment Subadvisory Agreement with Trillium are available in the Balanced Fund’s Semi-Annual Report to shareholders for the fiscal period ending January 31, 2022.

Fees. For the services Green Century Capital Management and Trillium provide the Balanced Fund, they receive a total of 0.65% of the average daily net assets of the Fund up to $250 million and 0.60% of the average daily net assets of the Fund in excess of $250 million. For the services Green Century Capital Management and Trillium provided the Balanced Fund during the fiscal year ended July 31, 2022, they received a total of 0.63% of the average daily net assets of the Fund.

THE GREEN CENTURY EQUITY FUND

Investment Adviser. Green Century Capital Management is the investment adviser for the Equity Fund and oversees the portfolio management of the Equity Fund on a day-to-day basis. Green Century Capital Management’s role is to ensure that the Equity Fund’s investment objective and environmental, social, governance and investment policies are accurately and effectively implemented. Green Century Capital Management has served as the Equity Fund’s investment adviser since 2006 and as the administrator of the Equity Fund since the commencement of operations of the Equity Fund.

Investment Subadviser. Northern Trust Investments, Inc. (NTI), 50 South LaSalle Street, Chicago, IL 60603, a subsidiary of Northern Trust Corporation, serves as the Subadviser for the Equity Fund. NTI is an Illinois State Banking Corporation and an investment adviser registered under the Investment Advisers Act of 1940, as amended. It primarily manages assets for institutional and individual separately managed accounts, investment companies and bank common and collective funds. Northern Trust Corporation is regulated by the Board of Governors of the Federal Reserve System as a financial holding company under the U.S. Bank Holding Company Act of 1956, as amended.

NTI conducts the day-to-day investment management for the Fund consistent with the guidelines set by Green Century Capital Management. NTI determines what securities shall be purchased, sold or exchanged to track the composition of the KLD400 ex Fossil Fuels Index. NTI does not determine the composition of the KLD400 ex Fossil Fuels Index.

As of September 30, 2022, Northern Trust Corporation, through its affiliates, had approximately $1.2 trillion in assets under management. NTI is paid by the Adviser (not the Fund).

The Portfolio Manager of the Equity Fund is Brent Reeder, Senior Vice President and Senior Portfolio Manager of NTI. Mr. Reeder has been manager of the Fund since November 29, 2010. He is primarily responsible for the day-to-day investment management of the Fund. Mr. Reeder has been employed as a portfolio manager with NTI since 1993. Since then, he has been a portfolio manager in the quantitative management group and is responsible for the management of various equity and equity index portfolios. The Statement of Additional Information contains additional information about Mr. Reeder, his compensation, other accounts he manages, and his ownership of shares of the Equity Fund.

Discussions regarding the basis of the Board of Trustees’ approval of the continuance of the Equity Fund’s Investment Advisory Agreement with Green Century Capital Management and Investment Subadvisory Agreement with NTI are available in the Equity Fund’s Semi-Annual Report to shareholders for the fiscal period ended January 31, 2022.

Disclosures Pertaining to the MSCI KLD 400 Social ex Fossil Fuels Index. The Green Century Equity Fund (the “Fund”) is not sponsored, endorsed, or promoted by MSCI, its affiliates, information providers or any other third party involved in, or related to, compiling, computing or creating the MSCI indices (the “MSCI Parties”), and the MSCI Parties bear no liability with respect to the Fund or any index on which the Fund is based. The MSCI Parties are not sponsors of the Fund and are not affiliated with the Fund in any way. The Statement of Additional Information contains a more detailed description of the limited relationship the MSCI Parties have with Green Century Capital Management and the Fund.

Fees. For the services Green Century Capital Management and NTI provide to the Equity Fund, they receive a total of 0.25% of the average daily net assets of the Fund up to but not including $100 million, 0.22% of the average daily net assets of the Fund from and including $100 million up to but not including $500 million, 0.17% of the average daily net assets of the Equity Fund from and including $500 million up to but not including $1 billion, and 0.12% of the average daily net assets of the Equity Fund equal to or in excess of $1 billion, computed and accrued daily. For the services Green Century Capital Management and NTI provided to the Equity Fund during the fiscal year ended July 31, 2022, they received a total of 0.22% of the average daily net assets of the Fund.

GREEN CENTURY INTERNATIONAL INDEX FUND

Investment Adviser. Green Century Capital Management is the investment adviser for the International Index Fund and oversees the portfolio management of the International Index Fund on a day-to-day basis. Green Century Capital Management’s role is to ensure that the International Index Fund’s investment objective and environmental, social, governance and investment policies are accurately and effectively implemented. Green Century Capital Management has served as the International Index Fund’s investment adviser and administrator since the commencement of operations of the International Index Fund.

Investment Subadviser. Northern Trust Investments, Inc. (NTI), 50 South LaSalle Street, Chicago, IL 60603, a subsidiary of Northern Trust Corporation, serves as the Subadviser for the International Index Fund. NTI is an Illinois State Banking Corporation and an investment adviser registered under the Investment Advisers Act of 1940, as amended. It primarily manages assets for institutional and individual separately managed accounts, investment companies and bank common and collective funds. Northern Trust Corporation is regulated by the Board of Governors of the Federal Reserve System as a financial holding company under the U.S. Bank Holding Company Act of 1956, as amended.

NTI conducts the day-to-day investment management for the Fund consistent with the guidelines set by Green Century Capital Management. NTI determines what securities shall be purchased, sold or exchanged to track the composition of the World ex USA SRI ex Fossil Fuels Index. NTI does not determine the composition of the World ex USA SRI ex Fossil Fuels Index.

As of September 30, 2022, Northern Trust Corporation, through its affiliates, had approximately $1.2 trillion in assets under investment management. NTI is paid by the Adviser (not the Fund).

The Portfolio Managers of the International Index Fund are Steven Santiccioli, Vice President and Senior Portfolio Manager, and Brent Reeder, Senior Vice President and Senior Portfolio Manager, of NTI. Mr. Santiccioli and Mr. Reeder have been managers of the Fund since its inception. They are jointly and primarily responsible for the day-to-day investment management of the Fund. Mr. Santiccioli has been employed as a portfolio manager with NTI since 2003. Mr. Reeder been employed as a portfolio manager with NTI since 1993. The Statement of Additional Information contains additional information about Mr. Santiccioli and Mr. Reeder, their compensation, other accounts they manage, and their ownership of shares of the International Index Fund.

Discussions regarding the basis of the Board of Trustees’ approval of the continuance of the International Index Fund’s Investment Advisory Agreement with Green Century Capital Management and Investment Subadvisory Agreement with NTI are available in the International Index Fund’s Semi-Annual Report to shareholders for the fiscal period ended January 31, 2022.

Disclosures Pertaining to the MSCI World ex USA SRI ex Fossil Fuels Index. The International Index Fund (the “Fund”) is not sponsored, endorsed, or promoted by MSCI, its affiliates, information providers or any other third party involved in, or related to, compiling, computing or creating the MSCI indices (the “MSCI Parties”), and the MSCI Parties bear no liability with respect to the Fund or any index on which the Fund is based. The MSCI Parties are not sponsors of the Fund and are not affiliated with the Fund in any way. The Statement of Additional Information contains a more detailed description of the limited relationship the MSCI Parties have with Green Century Capital Management and the Fund.

Fees. For the services Green Century Capital Management and NTI provide to the International Index Fund, Green Century Capital Management receives a total of 0.28% of the average daily net assets of the Fund. For the services Green Century Capital Management and NTI provided to the International Index Fund during the fiscal year ended July 31, 2022, they received a total of 0.28% of the average daily net assets of the Fund. From those fees, Green Century Capital Management pays NTI a subadvisory fee.

THE GREEN CENTURY FUNDS

Administrator. Green Century Capital Management serves as the Administrator of the Green Century Funds. Green Century Capital Management pays all the expenses of each Fund except each Fund’s investment advisory fees; any Distribution Plan fees; interest, taxes, brokerage costs and other capital expenses; expenses of the non-interested Trustees of the Funds (including counsel fees); and any extraordinary expenses.

Each Fund pays Green Century Capital Management an administrative fee such that, immediately following any payment to Green Century Capital Management, the total annual operating expenses of each class of the Fund do not exceed the following amounts:



Fund		% of average daily net assets
Balanced Fund
— Individual Investor Class:		1.48% up to $250 million, times the percentage of the net assets of the Fund attributable to the Fund’s Individual Investor share class and 1.43% in excess of $250 million, times the percentage of the net assets of the Fund attributable to the Fund’s Individual Investor share class
— Institutional Class:		1.18% up to $250 million, times the percentage of the net assets of the Fund attributable to the Fund’s Institutional share class and 1.13% in excess of $250 million, times the percentage of the net assets of the Fund attributable to the Fund’s Institutional share class
Equity Fund
— Individual Investor Class:		1.25%
— Institutional Class:		0.95%
International Index Fund
— Individual Investor Class:		1.28%
— Institutional Class:		0.98%

For the most recent fiscal year, the Administrator received annual fees of 0.83% of the Balanced Fund’s Individual Investor Class average daily net assets, 0.53% of the Balanced Fund’s Institutional Class average daily net assets, 1.03% of the Equity Fund’s Individual Investor Class average daily net assets, 0.73% of the Equity Fund’s Institutional Class average daily net assets, 1.00% of the International Index Fund’s Individual Investor Class average daily net assets and 0.70% of the International Fund’s Institutional Class average daily net assets.

The Administrative Services Agreement between the Green Century Funds and Green Century Capital Management provides that it should remain in force until terminated. The Agreement may be terminated as to any Fund at any time, without the payment of any penalty, by the Board of Trustees of the Green Century Funds or by Green Century Capital Management, in each case on not less than 30 days’ written notice to the other party.

Subadministrator. UMB Fund Services, Inc. (UMBFS) serves as the subadministrator of the Funds. UMBFS is responsible for conducting certain administrative services for the Funds subject to the direction of Green Century Capital Management. UMBFS receives a fee from the Administrator (not the Funds).

Distributor. UMB Distribution Services, LLC, an affiliate of UMBFS, serves as the Distributor of the shares of the Funds.

Transfer Agent. Atlantic Shareholder Services, LLC (Atlantic) is the transfer agent and shareholder services provider for the Green Century Funds.

Custodian. UMB Bank, n.a. (UMB Bank) is the custodian for the Green Century Funds.

Independent Registered Public Accounting Firm. KPMG LLP is the Independent Registered Public Accounting Firm of the Green Century Funds.

YOUR ACCOUNT



For information on opening an account, purchases, redemptions, balances, and other account services 8:00 am – 6:00 pm Eastern Time, Monday through Friday		1-800-221-5519

For daily share price information 24 hours per day		www.greencentury.com

For information about the Green Century Funds 9:00 am – 6:00 pm Eastern Time, Monday through Friday		1-800-93-GREEN (1‑800‑934‑7336) or [email protected]

For account registration forms, additional materials, and to sign up for E-Delivery of shareholder statements and reports		1-800-93-GREEN (1‑800‑934‑7336) or [email protected] or www.greencentury.com

HOW TO INVEST

You may invest in the Green Century Funds directly or through an intermediary, such as a financial advisor or a brokerage account.

Directly. Read the following information and complete the forms sent you with this prospectus and available online at www.greencentury.com. You may also open an account online at www.greencentury.com/open-an-account/. If you need additional account registration forms, call 1‑800‑934‑7336, email [email protected] or visit www.greencentury.com. (Click on “Forms + Documents” on the website’s home page.)

Through a financial intermediary. Consult your financial advisor, broker, mutual fund supermarket or other intermediary for details on how to invest in a Green Century Fund. The financial intermediary may have different policies from those described below. An intermediary may also charge a fee for its services.

When you invest directly, shares of the Funds are purchased at net asset value with no front-end sales charge and no contingent deferred sales charge when redeemed. However, if you invest in shares of a Fund through an investment professional or financial intermediary, that investment professional or financial intermediary may charge you a commission in an amount determined and separately disclosed to you by that investment professional or financial intermediary.

Because the Funds are not party to any commission arrangement between you and your investment professional or financial intermediary, any purchases and redemptions of Fund shares will be made by a Fund at the applicable net asset value (before imposition of the sales commission). Any commissions charged by an investment professional or financial intermediary are not reflected in the fees and expenses listed in each Fund’s fee table or expense example in this prospectus nor are they reflected in each Fund’s performance in the bar chart and table in this prospectus because these commissions are not charged by the Funds.

TYPES OF ACCOUNTS


Regular Investment Account		Individuals, businesses, trusts, and non-profit institutions may open regular investment accounts.

Traditional IRA & Roth IRA		Please read the Green Century Funds IRA Disclosure Statement before opening an IRA. You may contribute up to $6,500 for 2023 into a Green Century Funds Traditional IRA or Roth IRA. (If you are 50 years of age or older, the limit is $7,500 for 2023.) Individuals not covered by a retirement plan at work and people covered by a retirement plan who meet certain Internal Revenue Service (“IRS”) income guidelines may be able to deduct their contributions to a Traditional IRA from their taxable income each year. When you retire, distributions from your Traditional IRA are generally taxed as ordinary income. Roth IRAs differ from Traditional IRAs. With a Roth IRA you cannot deduct your current-year contributions from your taxable income; however, upon retirement, distributions from your Roth IRA are generally not taxed as ordinary income. More information is included in the Green Century Funds IRA Disclosure Statement.

SEP-IRA		A Simplified Employee Pension (SEP) plan allows self-employed people and small business owners to establish SEP-IRAs for the business owner and eligible employees. SEP-IRAs have specific eligibility rules and contribution limits (as described on IRS Form 5305-SEP); otherwise SEP-IRAs follow the same rules as Traditional IRAs. If you are interested in opening a Green Century Funds SEP-IRA Account, in addition to reading the IRA Disclosure Statement and filling out an IRA Account Registration Form, you will also need to complete IRS Form 5305-SEP. You may obtain the 5305-SEP form at the IRS website, www.irs.gov, by calling 1-800-93-GREEN, by emailing [email protected] or online at www.greencentury.com/forms-documents.

IRA Transfer/ Rollover		If you have an existing IRA that you would like to transfer to the Green Century Funds, or if you have a 401(k) account with a past employer that you would like to rollover into a Green Century Funds IRA, please review the Green Century Funds IRA Disclosure Statement, complete the IRA Account Registration form AND complete the Green Century Funds IRA Transfer Request Form. More information is included in the Green Century Funds IRA Disclosure Statement.

UGMA/ UTMA		Uniform Gifts to Minors (UGMA) and Uniform Transfers to Minors (UTMA) accounts may provide you with tax advantages as you put aside savings for your children or other minors. To open an UGMA or UTMA account, simply use the regular Green Century Funds Account Registration form and fill in the appropriate information under the “Gift To Minor” section.


Coverdell Education Savings Account		Coverdell Education Savings Accounts are designed to be tax-advantaged vehicles to save for childrens’ educational expenses. You may open an Education Savings Account by completing the Education Savings Account Registration Form. You may also transfer an existing Education Savings Account to a Green Century Funds Education Savings Account by completing both the Registration Form and the Education Savings Account Transfer Request Form. Please read the Green Century Funds Education Savings Account Disclosure Statement for additional information before opening an Education Savings Account.

Other Account Types		If this list does not contain the type of account in which you are interested, please call 1‑800‑934‑7336 and let us know what you are seeking; we may be able to accommodate you.

		It is the Green Century Funds’ policy not to accept accounts that are an investment option of a government entity’s participant-directed plan or program, as defined in Rule 206(4)-5 of the Investment Advisors Act of 1940.

CHOOSING A SHARE CLASS

Each of the Funds offer two share classes, the Individual Investor share class and the Institutional share class. Each share class is invested in the same portfolio of securities but each class has its own expense structure and minimums. It is more expensive to invest in the Individual Investor share class than in the Institutional share class. The minimum initial investments, as listed below, are higher for the Institutional share class than for the Individual Investor share class. Individuals as well as institutions who invest $250,000 or more may invest in the Institutional share class. Institutions as well as individuals may invest in the Individual Investor share class.

ACCOUNT MINIMUMS

To Open an Account

Individual Investor Class


Regular Investment Account*			$2,500
Individual Retirement Account—Traditional IRA, Roth IRA, SEP-IRA and SIMPLE IRA			$1,000
Coverdell Education Savings Account (formerly Education IRA)			$1,000
Uniform Gifts or Transfers to Minors Account (UGMA/UTMA)			$1,000

* A minimum initial investment of only $1,000 is required for investors who wish to open a regular investment account with a $100 or more per month Automatic Investment Plan.

Institutional Class


All types of Accounts			$250,000

The Funds reserve the right to waive the above minimums.

To Add to an Account

Individual Investor Class and Institutional Class


By Check, Wire or Exchange			$100
By Automatic Investment Plan or Online			$50

HOW TO PURCHASE SHARES

Opening an Account

To help fight the funding of terrorism and money laundering activities, federal law requires all financial institutions to obtain, verify, and record information that identifies each person who opens an account. When you open an account, you must provide the name, street address, date of birth, and Social Security or Tax Identification Number for each person on the account registration form. The Funds will use this information to identify you and may also ask for other identifying information. For a U.S. citizen living abroad, additional information will be required. Please call 1-800-221-5519 weekdays from 8:00 a.m. to 6:00 p.m.


Mail		To open an account by check, please complete and sign the registration form. See also Purchases by Check on page 65. Mail the form with a check made payable to the Green Century Balanced Fund, the Green Century Equity Fund or the Green Century International Index Fund (or to the Green Century Funds). Please note that there may be a delay in receipt of purchase requests sent by regular mail to a post office address.
		Green Century Funds
		P.O. Box 588
		Portland, ME 04112

		Should you wish to send the registration form and check via an overnight delivery service, use the following address:
		Green Century Funds
		c/o Apex Fund Services
		Three Canal Plaza, Ground Floor
		Portland, ME 04101

Online		To open an account online, please go to www.greencentury.com/open-an-account/. Once you complete the online registration process, money to fund your new Green Century account will be transferred from the bank account you provided. The following account types can be opened online: Regular Investment Accounts (individual or joint), Traditional IRAs (except rollovers or transfers), Roth IRAs (except rollovers or transfers) and UGMA/UTMA accounts.


		Before proceeding, please have the following ready: • Your Social Security Number • Your bank account and bank routing number (located on a check from your checking account or a deposit slip from your savings account) • The names, dates of birth and Social Security Numbers of any account beneficiaries (for IRAs only) Purchases made via Automated Clearing House (ACH) are limited to no more than $25,000 per day.

Wire		You may also open an account by instructing your bank to wire Federal funds (monies of member banks within the Federal Reserve System) to the Green Century Funds’ bank. Your bank may impose a fee for sending a wire. The Funds will not be responsible for the consequences of delays, including delays in the banking or Federal Reserve wire systems.

		Please call 1-800-221-5519 weekdays from 8:00 a.m. to 6:00 p.m. Eastern Time to obtain an account number and for more information about how to purchase shares by wire including bank wiring instructions. After calling, complete the registration form and mail it to the address given above.

Exchange		Individual Investor Class

		You may also open an account in one of the Funds by exchanging shares with a value of $2,500 or more ($1,000 for an IRA, Education Savings Account or UGMA/UTMA account) from another Green Century Fund. Your new account will be established using the same name(s) and address as your existing account.

		Institutional Class

		You may also open an account in one of the Funds by exchanging shares with a value of $250,000 or more from another Green Century Fund. Further, you may open an account in a Fund’s Institutional Class by exchanging shares with a value of $250,000 or more from that Fund’s Individual Investor Class. Your new account will be established using the same name(s) and address as your existing account.



		Individual Investor Class and Institutional Class

		To exchange by telephone, call 1-800-221-5519 weekdays from 8:00 a.m. to 6:00 p.m. Eastern Time. To exchange by letter, write to the Green Century Funds at the address given above, including the name of the Fund from which you are exchanging, the registered name(s) of ownership and address, the account number, the dollar amount or number of shares to be exchanged and the Fund into which you are exchanging. Sign your name(s) exactly as it appears on your account statement. The exchange requirements for corporations, other organizations, trusts, fiduciaries, institutional investors and retirement plans may be different from those for individual accounts. Please call 1-800-221-5519 for more information. Please note that there may be a delay in receipt of purchase requests sent by regular mail to a post office address. The Funds reserve the right to modify or terminate the exchange privilege upon 60 days’ prior written notice to shareholders.

		If you exchange your shares within 60 days of purchase or acquisition through exchange, you will be charged a redemption fee equal to 2.00% of the net asset value of the shares exchanged. However, the redemption fee will not apply to exchanges of shares acquired through the reinvestment of dividends or distributions. To calculate the redemption fees, a Fund will use the first-in, first-out (FIFO) method to determine which shares are being exchanged. Under this method, the date of exchange will be compared with the earliest date shares were acquired for the account. The Funds reserve the right to modify the terms of, or to terminate, the fee at any time.


		Certain shareholders of a Fund may be eligible to exchange their shares for shares of another share class of the same Fund. Generally, shareholders will not recognize a gain or loss for Federal Income tax purposes upon such an exchange. Shareholders invested via a financial intermediary should contact the financial intermediary for more information.

Automatic Investment Plan		Individual Investor Class You may open a Regular Investment Account with a minimum initial investment of $1,000 per Fund if you enroll in the Automatic Investment Plan and invest a minimum of $100 a month through the Plan. You may also add the Automatic Investment Plan to any account type. Complete and sign the registration form, including the Automatic Investment Plan section and mail it to: Green Century Funds, P.O. Box 588, Portland, ME 04112. You may also open an Automatic Investment Plan account online (Regular Investment Accounts, Traditional IRAs and Roth IRAs only) at www.greencentury.com/open-an-account/. You may terminate your participation in the Automatic Investment Plan at any time with written notification to the Funds at the same address. See also “Minimum Balances” on page 63.


		Institutional Class You may establish an Automatic Investment Plan when you open an account. Complete and sign the registration form, including the Automatic Investment Plan section and mail it to: Green Century Funds, P.O. Box 588, Portland, ME 04112. You may also open an Automatic Investment Plan account online (Regular Investment Accounts, Traditional IRAs and Roth IRAs only) at www.greencentury.com/open-an-account/. You may terminate your participation in the Automatic Investment Plan at any time with written notification to the Funds at the same address.

Making Additional Investments


Mail		You may make subsequent investments by submitting a check for $100 or more with the remittance form sent to you with your account statement. You may also mail your check with a letter of instruction indicating the amount of your purchase, your account number, and the name in which your account is registered, to the following address. Please note that there may be a delay in receipt of purchase requests sent by regular mail to a post office address. See also Purchases by Check on page 65.
		Green Century Funds P.O. Box 588 Portland, ME 04112


		For overnight delivery services, send to:
		Green Century Funds c/o Apex Fund Services Three Canal Plaza, Ground Floor Portland, ME 04101

Online		You may purchase additional shares online if you have signed up for this service. See Online Services on page 64. Purchases made via Automated Clearing House (ACH) are limited to no more than $25,000 per day.

Telephone		You may also make subsequent investments by telephoning 1-800-221-5519 if your bank account is registered with the Funds.

Wire		You may also make additional investments by instructing your bank to wire Federal funds. Your bank may impose a fee for sending the wire. The Green Century Funds cannot be responsible for the consequences of delays, including delays in the banking or Federal Reserve wire systems. Call 1-800-221-5519 weekdays from 8:00 a.m. to 6:00 p.m. Eastern Time for bank wiring instructions.

Exchange		Follow instructions under Opening an Account, above.


Automatic Investment Plan		You may arrange to make regular investments through automatic deductions from your checking or savings account. If you wish to select this option, please complete the appropriate section on your registration form. If you wish to set up an Automatic Investment Plan after opening an account, please call 1-800-93-GREEN, e-mail [email protected] or go to www.greencentury.com/forms-documents for an Automatic Investment Plan form. You may terminate your participation in the Automatic Investment Plan at any time with written notification to the Funds at P.O. Box 588, Portland, ME 04112.

HOW TO SELL SHARES (REDEMPTIONS)

You can take money out of your account at any time by selling (redeeming) some or all of your shares. See also Processing Time on page 66.



Telephone		You may redeem shares by telephone (unless you chose not to allow this option on your registration form). Call 1-800-221-5519 to request a redemption. You must provide your name, address, Fund account number and Social Security number before you may redeem shares by telephone. All telephone redemption requests are recorded.

		If you chose not to allow telephone redemption on your registration form and now wish to redeem by telephone, call 1-800-221-5519 for more information or download the Telephone Redemption Option form at www.greencentury.com/forms-documents.


Mail		In order to redeem your shares by mail from an account that is not an IRA account, complete the Redemption Request Form. To redeem your shares by mail from an IRA account, complete the IRA Distribution Election and Authorization Form. Both forms are available by calling 1‑800‑221‑5519 or by downloading the form at www.greencentury.com/forms-documents. If you wish, you may instead send a letter to the Green Century Funds and include the Fund name, the account registration name(s) and address, the account number, and the dollar amount or the number of shares you wish to redeem, signed exactly as your name appears on your account statement. You may be required to obtain a Signature Guarantee on the form or the letter (see below). Please note that there may be a delay in receipt of redemption requests sent by regular mail to a post office address. Mail your form or letter to:
		Green Century Funds P.O. Box 588 Portland, ME 04112

Online		You may redeem shares online in any non-retirement account if you have signed up for this service. Online redemption is not available for shares held in IRA accounts. See Online Services on page 64.

Important Information About Redemptions


Minimum Balances		Individual Investor Class
Minimum Balances		Shareholders are encouraged to maintain a share balance of at least $2,500. Individual Retirement Accounts, Education Savings Accounts and Uniform Gifts or Transfers to Minors Act accounts have a $1,000 minimum balance requirement. The Funds reserve the right, following 60 days’ written notice to shareholders, to redeem all shares in accounts with balances less than the minimum. The Funds will mail the proceeds of the redeemed account to the shareholder. This provision does not apply to Automatic Investment Plan accounts. If the value of your account falls below the minimum as a result of market activity, an involuntary redemption will not be triggered.

		Institutional Class
		Shareholders are encouraged to maintain a share balance of at least $250,000 for all account types. The Funds reserve the right, following 60 days’ written notice to shareholders, to redeem all shares in accounts with balances less than the minimum or to convert those Institutional Class shares to Individual Investor Class shares. The Funds will mail the proceeds of the redeemed account to the shareholder. If the value of your account falls below the minimum as a result of market activity, an involuntary redemption will not be triggered.

Redemption Fee		If you redeem your shares within 60 days of purchase or acquisition through exchange, you will be charged a redemption fee equal to 2.00% of the net asset value of the shares redeemed. However, the redemption fee will not apply to redemptions of shares acquired through the reinvestment of dividends or distributions. The redemption fee will also not apply to redemptions of shares of one share class to purchase shares of another share class in the same Fund. The fee is charged for the benefit of remaining shareholders and will be paid to the Fund to help offset transaction costs the Fund may incur due to excess short-term trading in the Fund. To calculate the redemption fees, a Fund will use the first-in, first-out (FIFO) method to determine which shares are being redeemed. Under this method, the date of redemption or exchange will be compared with the earliest date shares were acquired for the account. The Funds reserve the right to modify the terms of, or to terminate, the fee at any time.

		In some cases, the Funds may be offered through certain financial intermediaries whose redemption fee policies may differ from those of the Funds. If you purchase Fund shares through a financial intermediary, please contact the intermediary regarding its policies on redemption fees and market timing.



Receiving your money	By check via U.S. mail	No charge
	Online (if you have signed up for this service) to the authorized bank account of record for your account	No charge
	By check via overnight delivery	$30
	Wired to the authorized bank account of record for your account	$10


Signature Guarantees		A signature guarantee—which is different from a notarized signature—is a warranty that the signature presented is genuine. You can obtain a signature guarantee from most banks, brokerage firms and savings institutions where you have an account. Be sure to ask for a “New Technology” Medallion Signature Guarantee Stamp. A notary public cannot provide a signature guarantee. A signature guarantee may be required for the signature of each person in whose name the account is registered.

		You must obtain a signature guarantee in any of the following situations: • You request in writing a redemption of $10,000 or more • You request a redemption check payable to someone other than the account owner(s) • You request that a redemption check be sent to an address other than the address of record on the account • You request a redemption and you have changed your address of record within the last 30 days • You request a wire or electronic funds transfer to a bank account other than the bank account of record on the account • Any change to account ownership or registration • Adding or changing the bank account of record for the account
		• Authorizing telephone redemption, if not already authorized on the account • Authorizing online transactions, if not already authorized on the account

		Green Century reserves the right to require a signature guarantee in other situations as well.

Other Account Types		The redemption requirements for corporations, other organizations, trusts, fiduciaries, institutional investors and Individual Retirement Accounts (IRAs) may be different from those for regular accounts. For more information, please call 1-800-221-5519.

ONLINE SERVICES

You may access your account, conduct transactions, and view statements online by signing up for Online Services. After opening an account, visit www.greencentury.com and click on “Access My Account.” On the login screen, click where indicated to establish Online Account Access and follow the instructions given on the website. You will need your account number and Social Security or Tax Identification Number to register to add Online Access to your account.

You also have the option of selecting electronic delivery of your account statements, shareholder reports, and other documents. If you would like to receive documents electronically, log on to your account at https://greencentury.access-my-account.com and click “Account Detail.” If you opt for electronic document delivery, you will automatically receive an e-mail letting you know when documents are available online.

If you have questions about online services or need technical assistance, call 1-800-221-5519 Monday through Friday, 8:00 am to 6:00 pm Eastern Time.

TRANSACTION INFORMATION

Purchases by Check. Checks must be made payable to the Green Century Balanced Fund, the Green Century Equity Fund or the Green Century International Index Fund (or to the Green Century Funds). No third party corporate checks will be honored. For individual, joint, sole proprietorship, IRA and UGMA/UTMA accounts, checks may be made payable to one or more owners of the account and endorsed to the Fund(s). Checks also must be drawn on or payable through a U.S. bank and be in U.S. dollars. No cash deposits, travelers checks, credit card checks, money orders or counter checks will be accepted. If you purchase shares with a check that is returned due to insufficient funds, your purchase will be canceled and you will be responsible for any losses or fees incurred in the transaction.

Customer Identification Verification Procedures. Federal law requires all financial institutions, including the Green Century Funds, to obtain, verify and record information that identifies each person who opens an account. In order to open a new account, the Funds will ask you for your name, street address, date of birth, and Social Security or Tax Identification Number. If the Funds or their Transfer Agent do not have a reasonable belief as to the identity of a customer, the account may be rejected or the shareholder may be blocked from conducting further transactions on the account in accordance with applicable law until such information is received in good order. The Funds also reserve the right to close an account within 20 business days of the date the account was opened at the net asset value of the Fund on the day the account is closed if clarifying information or documentation as to the identity of the shareholder is not received. The Funds further reserve the right to close an account if, in the opinion of the Funds or their Transfer Agent, the account is suspected of being opened for fraud or money laundering purposes. The Funds or their Transfer Agent will correspond with the prospective shareholders advising them of the reasons their account has been rejected and what, if any, information as required by the USA PATRIOT Act is necessary to allow the account to be accepted.

Account Information Changes. To change the address on an account, you may call the Green Century shareholder services office at 1-800-221-5519 or send Green Century the information in writing as described below. To change any other information regarding an account (including a change of beneficiary or change in the automatic investment plan), you must send Green Century this information in writing. Please mail the new information to: Green Century Funds, P.O. Box 588, Portland, ME 04112. Include your Green Century account number, your name, address, signature and phone number, along with the new information. If you prefer, you may fax this information to: Green Century Funds, 207-347-2195. You may confirm receipt of this information by calling the Green Century shareholders services office at 1-800-221-5519.

Please note that the following account information changes require a signature guarantee:

•

Any change to account ownership or registration

•

Adding or changing the bank account of record for the account

•

Authorizing telephone redemption, if not already authorized on the account

•

Authorizing online transactions, if not already authorized on the account

Green Century reserves the right to require a signature guarantee in other situations. For more information about signature guarantees, see Signature Guarantees on page 64.

Joint Accounts. The Funds’ policy on the rights of joint account owners provides that any account owner has the authority to act on the account without notice to the other account owner(s). There is an exception to this policy for some corporate accounts for which two signatures are explicitly required per written instructions on file for the account. In addition, the Funds, at their sole discretion and for their protection and that of other shareholders, may require the written consent of all account owners prior to acting upon the instructions of any account owner.

Large Redemptions. If during any 90-day period, you redeem Fund shares worth more than $250,000 (or 1% of the Fund’s assets if that percentage is less than $250,000), the Fund reserves the right to pay all or part of the redemption proceeds in-kind, that is, in securities rather than in cash. If payment is made in-kind, you may incur brokerage commissions if you elect to sell the securities for cash.

Confirmation of Transactions. All purchases and redemptions will be confirmed promptly. Usually a confirmation of your purchase or sale of Fund shares will be mailed by the second business day following receipt of your instructions. Automatic reinvestments of distributions and systematic investments and withdrawals may be confirmed only by quarterly statements.

Share Price Calculation. Once each day that the New York Stock Exchange is open for trading, the share price for each share class of each Fund is calculated. This is the share class’ Net Asset Value (the NAV). Because the Green Century Funds are no-load, this is also the offering price at which each share is sold. Shares are purchased and/or sold at the next share price calculated after your order is received in good form.

All purchase and redemption requests received in good order by the Funds’ transfer agent or an authorized agent are executed, without a sales charge, at the next-determined net asset value. The authorized agent is responsible for transmitting your request to the Funds in a timely manner. Reinvested dividends receive the net asset value as of the ex-dividend date. Note however that if you redeem shares within 60 days of purchase, a 2.00% redemption fee will be charged. For additional information, see How to Sell Shares (Redemptions) on page 62.

Processing Time. When you redeem, the Funds will normally send your redemption proceeds on the next day the New York Stock Exchange is open for trading following the receipt of your redemption request in

good order by the Funds’ transfer agent or an authorized agent. The authorized agent is responsible for transmitting your request to the Funds in a timely manner. Payment of redemption proceeds may take up to seven days, or longer in the following cases:

Shares Recently Purchased by Check. If you purchase shares by check and redeem them by any method within 10 days of purchase, the Funds will release your redemption proceeds when your check clears. It is possible, although unlikely, that this could take up to 10 days. If you purchase shares by Federal funds wire, you may avoid this delay.

Shares Recently Purchased by Cashier’s Check. If you purchase shares by a cashier’s check, the Funds will hold your redemption proceeds for fifteen business days following the purchase.

Shares Purchased by Wire. If you open an account by wire, the Funds’ transfer agent will not be able to process a redemption request until it has received your completed and signed registration form.

Other Information Regarding Payment of Redemption Proceeds. Your redemption proceeds may be delayed, or your right to receive redemption proceeds suspended, if the NYSE is closed (other than on weekends or holidays) or trading is restricted, if the Securities and Exchange Commission determines that an emergency or other circumstances exist that make it impracticable for a Fund to sell or value its portfolio securities, or otherwise as permitted by the rules of or by the order of the Securities and Exchange Commission.

Under normal circumstances, each Fund expects to meet redemption requests by using cash or cash equivalents in its portfolio and/or selling portfolio assets to generate cash. Under stressed or abnormal market conditions or circumstances, including circumstances adversely affecting the liquidity of a Fund’s investments, a Fund may be more likely to be forced to sell portfolio assets to meet redemptions than under normal market circumstances. Under such circumstances, a Fund could be forced to liquidate assets at inopportune times or at a loss or depressed value. Each Fund also may pay redemption proceeds using cash obtained through borrowing arrangements that may be available from time to time.

Each Fund reserves the right to pay part or all of the redemption proceeds in kind, i.e., in securities, rather than cash. If a Fund redeems in kind, it generally will deliver to you a proportionate share of the portfolio securities owned by the Fund. Securities you receive this way may increase or decrease in value while you hold them and you may incur brokerage and transaction charges and tax liability when you convert the securities to cash. A Fund may redeem in kind at a shareholder’s request or if, for example, the Fund reasonably believes that a cash redemption may have a substantial impact on the Fund and its remaining shareholders.

During periods of deteriorating or stressed market conditions, when an increased portion of a Fund’s portfolio may be comprised of less-liquid investments, or during extraordinary or emergency circumstances, a Fund may be more likely to pay redemption proceeds with cash obtained through short-term borrowing arrangements (if available) or by giving you securities.

Sales of shares made less than 60 days after settlement of a purchase or acquisition through exchange will be subject to an early redemption fee, with certain exceptions. (See “Important Information About Redemptions—Redemption Fee” and “Policy on Market Timing” for more information.)

Tax Information. A redemption of shares, including an exchange into another Fund, is a sale of shares and may result in a gain or loss for income tax purposes. An exchange of shares of one class of a Fund directly for shares of another class of shares of that Fund normally should not be taxable for federal income tax purposes. Please see below for additional information on dividends and taxes.

Social Security or Tax Identification Number. Please complete the Social Security or Tax Identification Number section of the Funds’ registration form when you open an account. Federal tax law requires the Funds to apply backup withholding to dividends, capital gains distributions and redemption and exchange proceeds from accounts (other than those of certain exempt payees) without a Social Security or Tax Identification Number and certain other information or upon notification from the IRS or a broker that withholding is required. The backup withholding rate is currently 24%. The Funds reserve the right to reject new account registrations without a Social Security or Tax Identification Number. The Funds also reserve the right to close, by redemption, accounts without Social Security or Tax Identification Numbers.

Telephone Transaction Liability. All shareholders may initiate transactions (except redemptions) by telephone. To redeem shares by telephone, you must elect this option in writing. See page 62 for further information. Neither the Funds nor any of their service contractors will be liable for any loss or expense in acting upon any telephone instructions that are reasonably believed to be genuine. In attempting to confirm that telephone instructions are genuine, the Funds will use procedures that are considered to be reasonable, including requesting a shareholder to provide information about the account. To the extent that the Funds fail to use reasonable procedures to verify the genuineness of telephone instructions, the Funds and/or their service contractors may be liable for any losses due to telephone instructions that prove to be fraudulent or unauthorized.

Policy on Market Timing. Frequent purchases, exchanges and redemptions of Fund shares (often referred to as market timing or short-term trading) may hurt Fund performance by disrupting the management of the Fund’s portfolio and by increasing expenses. Because the International Index Fund invests significantly in non-U.S. securities, it may be particularly vulnerable to the risks of short-term trading. The Funds seek to discourage market timing and protect long-term shareholders through several methods. Pursuant to policies and procedures adopted by the Funds’ Board of Trustees, these methods include:

•

imposing a 2.00% redemption fee on the redemption or exchange of shares held less than sixty days (for more information on the redemption fee, see page 63);

•

using “fair value” pricing when appropriate so that an investor cannot purchase, redeem or exchange Fund shares at a price that does not reflect the fair value of a Fund’s portfolio;

•

monitoring shareholder account activity in order to detect patterns of frequent purchases, exchanges and sales, including those that appear to be made in response to short-term fluctuations in share price or in order to improperly avoid the imposition of the redemption fee; and

•

reserving the right to restrict or reject, limit, delay, or impose other conditions on, any exchange or purchase or to close a shareholder account based on a suspected history of market timing or if any particular transaction may adversely affect the interests of a Fund or its shareholders.

The Funds and Green Century Capital Management seek to apply the above fees and restrictions uniformly and will not waive them for any account. Neither the Funds nor Green Century Capital Management will enter into any arrangements to permit market timing in the shares of the Funds.

The Funds may not know the identity of shareholders in omnibus accounts and must rely on the assistance of the financial intermediary in whose name the account is held (a broker-dealer or retirement plan, for example). The Funds and/or their distributor or administrator, as appropriate and in accordance with applicable law, have entered into agreements with financial intermediaries requiring the intermediaries to collect the redemption fee and to provide certain information to help identify market timing activity and to prohibit further purchases or exchanges by a shareholder identified as having engaged in market timing. Because the Funds may not be able to detect all instances of market timing, particularly in omnibus accounts and where an investor may attempt to conceal its identity, the Funds cannot guarantee that they will be able to deter all instances of market timing or entirely eliminate short-term trading in shares of the Funds.

Reservations. Each Fund may stop offering its shares for sale at any time and may reject any order for the purchase or exchange of shares. Each Fund may also modify the conditions of purchase at any time. The Funds reserve the right to waive the minimum investment requirements; accounts opened with less than the minimum required amount may be subject to the minimum balances provisions. (See page 63). The Funds reserve the right to revise or terminate the telephone redemption privilege at any time, without notice. If the Funds suspend telephone redemption privileges, or if you have trouble getting through on the phone, you will still be able to redeem your shares by mail.

SHAREHOLDER ACCOUNT STATEMENTS

Shareholders will receive quarterly statements showing all account activity during that quarter, including dividends. Additional purchases and redemptions will be confirmed promptly, usually by the second business day after the purchase or redemption request is received. Automatic reinvestments of distributions and systematic investments and withdrawals may be confirmed only by quarterly statements. The Green Century Funds will send you detailed tax information on the amount and type of their dividends and distributions each year.

HOUSEHOLDING OF THE FUNDS’ MAILINGS TO ACCOUNTS HELD THROUGH FINANCIAL INTERMEDIARIES

For accounts held through financial intermediaries: To reduce expenses, the Funds may mail only one copy of the Funds’ Prospectus, each Annual and Semi-Annual Report and other regulatory documents to addresses at which two or more accounts are registered. If you wish to receive individual copies of these documents, please telephone 1-800-221-5519 or contact your financial institution. The Funds will begin sending you individual copies thirty days after receiving your request.

DIVIDENDS AND TAXES

The Funds normally declare and pay income dividends, if any, semi-annually in June and December and distribute net capital gains, if any, once a year in December. Each Fund intends to distribute substantially all of its income and net capital gains.

You may opt to receive distributions in cash (via check) or have them reinvested in additional shares of the Funds. Dividends and capital gain distributions are automatically reinvested unless you request otherwise. If you invest in an Individual Retirement Account (IRA), all dividends and capital gains distributions must be reinvested; however, if you are over 59¹⁄₂ years old, distributions from IRA accounts may be paid to you in cash (via check).

The following discussion is very general. You may wish to consult a tax adviser regarding the effect that an investment in a Fund may have on your own tax situation.

Taxability of Distributions. As long as a Fund qualifies for treatment as a regulated investment company (which each intends to do), it pays no federal income tax on the earnings it distributes to shareholders.

Unless you hold your shares in a tax-advantaged account (including a retirement account such as an IRA) you will normally have to pay federal income taxes, and any state or local taxes, on distributions you receive from a Fund, whether you take the distributions in cash or have them reinvested in additional shares. Non-corporate shareholders may be taxed at rates of up to 20% on distributions reported by a Fund as “qualified dividend income”. “Qualified dividend income” generally is income derived from U.S. corporations or certain foreign corporations that are either incorporated in a U.S. possession or eligible for benefits under certain U.S. income tax treaties. In addition, dividends that a Fund receives in respect of stock of certain foreign corporations may be “qualified dividend income” if that stock is readily tradable on an established U.S. securities market. Distributions reported as capital gain dividends are taxable as long-term capital gains without regard to the length of time you have held your shares. Long-term capital gains are generally taxed to non-corporate shareholders at rates of up to 20%. Other distributions are generally taxable as ordinary income. Distributions derived from interest on U.S. Government securities (but not distributions of gain from the sale of such securities) may be exempt from state and local taxes. Some dividends paid in January may be taxable as if they had been paid the previous December. A portion of dividends received from a Fund (but none of a Fund’s capital gain dividends) may qualify for the dividends-received deduction for corporate shareholders. Since the International Index Fund’s income is derived primarily from non-U.S. investments, it is not expected that a substantial portion of dividends paid by the International Index Fund will qualify for the dividends-received deduction for corporations.

A 3.8% Medicare contribution tax generally applies to all or a portion of the net investment income of a shareholder who is an individual and not a nonresident alien for federal income tax purposes and who has adjusted gross income (subject to certain adjustments) that exceeds a threshold amount. This 3.8% tax also applies to all or a portion of the undistributed net investment income of certain shareholders that are estates and trusts. For these purposes, dividends, interest and certain capital gains are generally taken into account in computing a shareholder’s net investment income.

If the International Index Fund meets certain requirements with respect to its holdings, it may elect to “pass through” to shareholders foreign taxes that it pays, in which case each shareholder will include the amount of such taxes in computing gross income, but will be eligible to claim a credit or deduction for such taxes, subject to generally applicable limitations on such deductions and credits. The International Index Fund’s investment in certain foreign securities or foreign currencies may accelerate the International Index Fund’s distributions to shareholders and increase the distributions taxed to shareholders as ordinary income.

After the end of each year, the Green Century Funds will send you detailed tax information on the amount and type of distributions and dividends you received during that year.

Distributions by a Fund will reduce that Fund’s net asset value per share. Therefore, if you buy shares shortly before the record date of a distribution, you may pay the full price for the shares and then effectively receive a portion of the purchase price back as a taxable distribution.

If you are neither a citizen nor a resident of the United States, each Fund will withhold U.S. federal income tax at the rate of 30% on taxable dividends and other payments that are subject to such withholding. You may be able to arrange for a lower withholding rate under an applicable tax treaty if you supply the appropriate documentation required by each Fund. This 30% withholding tax will not apply to dividends that a Fund reports as (a) interest-related dividends, to the extent such dividends are derived from the Fund’s “qualified net interest income,” or (b) short-term capital gain dividends, to the extent such dividends are derived from the Fund’s “qualified short-term capital gains.” “Qualified net interest income” is a Fund’s net income derived from U.S.-source interest and original issue discount, subject to certain exceptions and limitations. “Qualified short-term gain” generally means the excess of the net short-term capital gain of a Fund for the taxable year over its net long-term capital loss, if any.

Each Fund is also required in certain circumstances to apply backup withholding on dividends, redemption proceeds and certain other payments that are paid to any shareholder (including a shareholder who is neither a citizen nor a resident of the United States) who does not furnish to the Fund certain information and certifications or who is otherwise subject to backup withholding. The backup withholding rate is currently 24%. Backup withholding will not, however, be applied to payments that have been subject to the 30% withholding tax described in the preceding paragraph. Prospective investors in a Fund should read the Fund’s account registration form for additional information regarding backup withholding of federal income tax.

Unless certain non-U.S. entities that hold a Fund’s shares comply with IRS requirements that will generally require them to report information regarding U.S. persons investing in, or holding accounts with, such entities, a 30% withholding tax may apply to the Fund’s distributions payable to such entities. A non-U.S. shareholder may be exempt from the withholding described in this paragraph under an applicable intergovernmental agreement between the U.S. and a foreign government, provided that the shareholder and the applicable foreign government comply with the terms of such agreement.

Taxability of Transactions. When you redeem, sell or exchange shares, it is generally considered a taxable event for you. Depending on the purchase price and the sale price of the shares you redeem, sell or exchange, you may have a gain or loss on the transaction. You are responsible for any tax liabilities generated by your transactions.

VALUATION OF SHARES

Green Century Balanced Fund and Green Century Equity Fund. The net asset value per share of each class of each Fund is computed by dividing the value of the Fund’s total assets less its liabilities attributable to each class by the total number of shares outstanding of each class.

Equity securities and other instruments held by a Fund for which market quotations are readily available are generally valued at the last sale price on the exchange or market on which the security or instrument is primarily traded at the time of valuation. Securities listed on the NASDAQ Stock Market, Inc. (“NASDAQ”) are generally valued at the NASDAQ Official Closing Price. Debt securities held by a Fund are generally valued on the basis of valuations furnished by an independent pricing service. When a market price is not available, or when a Fund has reason to believe that the price does not reflect market realities, the Fund may value securities instead by using fair value methods. In such a case, a Fund’s value for a security may be different from quoted market values. Because the Green Century Balanced Fund invests primarily in the stocks and bonds of U.S. companies that are traded on U.S. exchanges and the Equity Fund invests primarily in the stocks of U.S. companies that are traded on U.S. exchanges, it is expected that there would be limited circumstances in which a Fund would use fair value pricing. A Fund may use fair value pricing if, for example, the exchange on which a portfolio security is principally traded closes early, trading in a particular security is halted during the day and does not resume prior to the time a Fund calculates its NAV, a portfolio security is thinly traded or a security’s issuer is in default or bankruptcy proceedings, in accrodance with the valuation designee’s fair value procedures. Green Century has been designated as the Funds’ valuations designee, with responsibility for fair valuation subject to oversight by the Funds Board of Trustees.

Green Century International Index Fund. The net asset value per share of each class of the Green Century International Index Fund is computed by dividing the value of the Fund’s total assets less its liabilities attributable to each class by the total number of shares outstanding of each class.

Equity securities and other instruments held by the Fund for which market quotations are readily available are generally valued at the last sale price on the exchange or market on which the security or instrument is primarily traded at the time of valuation. Securities listed on NASDAQ are generally valued at the NASDAQ Official Closing Price. Debt securities held by a Fund are generally valued on the basis of valuations furnished by an independent pricing service. The Fund uses a fair value model developed by an independent pricing service to assist in valuing non-U.S. securities. On a daily basis, the pricing service recommends changes, based on a proprietary model, to the closing market prices of each non-U.S. security held by the Fund to reflect the security’s fair value at the time the Fund determines its net asset value. The Fund applies these recommendations in accordance with the valuation designee’s fair value procedures. Green Century has been designated as the Funds valuations designee, with responsibility for fair valuation subject to oversight by the Fund Board of Trustees.

The valuations of securities traded in non-U.S. markets will often be determined as of the earlier closing time of the markets on which they primarily trade. When the Fund holds securities or other assets that are denominated in a foreign currency, the Fund will normally use the currency exchange rate as of 4:00 p.m. Eastern Time. Non-U.S. markets are open for trading on weekends and other days when the Fund does not price its shares. Therefore, the value of the Fund’s shares may change on days when you will not be able to purchase or redeem Fund shares.

When a market price is not available, or when the Fund has reason to believe that the price does not reflect market realities, the Fund may value securities instead by using fair value methods. In such a case, the Fund’s value for a security may be different from quoted market values. The Fund may use fair value pricing if, for example, the exchange on which a portfolio security is principally traded closes early, trading

in a particular security is halted during the day and does not resume prior to the time the Fund calculates the NAV for each share class, a portfolio security is thinly traded or a security’s issuer is in default or bankruptcy proceedings.

Green Century Funds. The net asset value per share of each share class of each Fund is determined every business day as of the scheduled close of regular trading of the New York Stock Exchange (usually 4:00 p.m. Eastern Time). If the New York Stock Exchange closes at another time, the Fund will calculate the NAV of each share class as of the scheduled closing time. For share prices 24 hours a day, visit www.greencentury.com/fund-performance.

SHARES AND VOTING RIGHTS

As with other mutual funds, investors purchase shares when they invest money in a Fund. Each share and fractional share of a class of the Fund entitles the shareholder to:

•

Receive a proportional interest in the assets of the Fund allocable to that class

•

Cast one vote for each dollar of net asset value (number of shares owned times net asset value per share) represented by a shareholder’s shares in a class of a Fund on certain Fund matters. Shares of a Fund vote together as a single class on certain matters, including the election of the Funds’ trustees and changes in fundamental policies. Share classes have exclusive voting rights with respect to matters affecting only that class.

The Funds are not required to hold annual meetings and, to avoid unnecessary costs, do not intend to do so except when certain matters, such as a change in its fundamental policies, must be decided. If a meeting is held and you cannot attend, you may vote by proxy. Before the meeting, the Funds will send you proxy materials that explain the issues to be decided and include instructions on voting.

FINANCIAL HIGHLIGHTS

The Financial Highlights table is intended to help you understand the Funds’ financial performance for the period of the Funds’ operations. Certain information reflects financial results for a single share of each Fund. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment (assuming reinvestment of all dividends and distributions). The information has been derived from the Funds’ financial statements which have been audited by KPMG LLP, whose reports, along with the Funds’ financial statements, are included in the Funds’ Annual Report which is available upon request.

GREEN CENTURY BALANCED FUND INDIVIDUAL INVESTOR CLASS

FINANCIAL HIGHLIGHTS


	For the Years Ended July 31,
	2022			2021			2020			2019			2018
Net Asset Value, beginning of year	$	37.21		$	30.83		$	29.05		$	27.05		$	25.55

Income (loss) from investment operations:
Net investment income (loss)		(0.01	)		0.02			0.11			0.12			0.07
Net realized and unrealized gain (loss) on investments		(2.78	)		7.51			2.25			2.50			1.79

Total increase (decrease) from investment operations		(2.79	)		7.53			2.36			2.62			1.86

Less dividends:
Dividends from net investment income		—			(0.02	)		(0.11	)		(0.11	)		(0.05	)
Distributions from net realized gains		(1.49	)		(1.13	)		(0.47	)		(0.51	)		(0.31	)

Total decrease from dividends		(1.49	)		(1.15	)		(0.58	)		(0.62	)		(0.36	)

Net Asset Value, end of year	$	32.93		$	37.21		$	30.83		$	29.05		$	27.05

Total return		(7.97	)%		24.86	%		8.19	%		10.04	%		7.32	%
Ratios/Supplemental data:
Net assets, end of year (in 000’s)	$	296,605		$	323,991		$	309,871		$	276,487		$	247,066
Ratio of expenses to average net assets		1.46	%		1.46	%		1.47	%		1.48	%		1.48	%
Ratio of net investment income to average net assets		(0.03	)%		0.07	%		0.37	%		0.44	%		0.25	%
Portfolio turnover(a)		9	%		17	%		25	%		19	%		18	%

(a)	Calculated at Fund level.

GREEN CENTURY BALANCED FUND INSTITUTIONAL CLASS

FINANCIAL HIGHLIGHTS


	For the Years Ended July 31, 2022			For the Period November 30, 2020 (Commencement of Operations) to July 31, 2021
Net Asset Value, beginning of period	$	37.27		$	33.58

Income (loss) from investment operations:
Net investment income		0.08			0.08
Net realized and unrealized gain (loss) on investments .		(2.78	)		4.78

Total increase (decrease) from investment operations		(2.70	)		4.86

Less dividends:
Dividends from net investment income		(0.02	)		(0.04	)
Distributions from net realized gains		(1.49	)		(1.13	)

Total decrease from dividends		(1.51	)		(1.17	)

Net Asset Value, end of period	$	33.06		$	37.27

Total return		(7.72	)%		14.89	%(a)
Ratios/Supplemental data:
Net assets, end of period (in 000’s)	$	101,317		$	86,347
Ratio of expenses to average net assets		1.16	%		1.16	%(b)
Ratio of net investment income to average net assets		0.27	%		0.33	%(b)
Portfolio turnover(c)		9	%		17	%(a)

(a)	Not annualized.

(b)	Annualized.

(c)	Calculated at Fund level.

GREEN CENTURY EQUITY FUND INDIVIDUAL INVESTOR CLASS

FINANCIAL HIGHLIGHTS


	For the Years Ended July 31,
	2022			2021			2020			2019			2018
Net Asset Value, beginning of year	$	71.35		$	52.23		$	46.17		$	43.16		$	38.05

Income from investment operations:
Net investment income		0.09			0.09			0.25			0.25			0.22
Net realized and unrealized gain (loss) on investments		(6.11	)		19.60			6.16			3.61			5.28

Total increase (decrease) from investment operations		(6.02	)		19.69			6.41			3.86			5.50

Less dividends:
Dividends from net investment income		(0.02	)		(0.06	)		(0.22	)		(0.21	)		(0.20	)
Distributions from net realized gains		(0.85	)		(0.51	)		(0.13	)		(0.64	)		(0.19	)

Total decrease from dividends		(0.87	)		(0.57	)		(0.35	)		(0.85	)		(0.39	)

Net Asset Value, end of year	$	64.46		$	71.35		$	52.23		$	46.17		$	43.16

Total return		(8.64	)%		37.90	%		13.95	%		9.33	%		14.52	%
Ratios/Supplemental data:
Net assets, end of year (in 000’s)	$	301,668		$	338,094		$	265,946		$	244,706		$	232,609
Ratio of expenses to average net assets		1.25	%		1.25	%		1.25	%		1.25	%		1.25	%
Ratio of net investment income to average net assets		0.11	%		0.14	%		0.52	%		0.58	%		0.53	%
Portfolio turnover(a)		5	%		9	%		10	%		14	%		18	%

(a)	Calculated at Fund level.

GREEN CENTURY EQUITY FUND INSTITUTIONAL CLASS

FINANCIAL HIGHLIGHTS


	For the Years Ended July 31,												For the Period April 30, 2018 (Commencement of Operations) to July 31, 2018
	2022			2021			2020			2019
Net Asset Value, beginning of period	$	71.12		$	52.10		$	46.11		$	43.16		$	40.86

Income from investment operations:
Net investment income		0.31			0.30			0.39			0.39			0.09
Net realized and unrealized gain (loss) on investments		(6.13	)		19.54			6.16			3.59			2.35

Total increase (decrease) from investment operations		(5.82	)		19.84			6.55			3.98			2.44

Less dividends:
Dividends from net investment income		(0.32	)		(0.31	)		(0.43	)		(0.39	)		(0.14	)
Distributions from net realized gains		(0.85	)		(0.51	)		(0.13	)		(0.64	)		—

Total decrease from dividends		(1.17	)		(0.82	)		(0.56	)		(1.03	)		(0.14	)

Net Asset Value, end of period	$	64.13		$	71.12		$	52.10		$	46.11		$	43.16

Total return		(8.38	)%		38.33	%		14.28	%		9.65	%		6.50	%(a)
Ratios/Supplemental data:
Net assets, end of period (in 000’s)	$	213,705		$	178,038		$	94,039		$	54,850		$	29,978
Ratio of expenses to average net assets		0.95	%		0.95	%		0.95	%		0.95	%		0.95	%(b)
Ratio of net investment income to average net assets		0.41	%		0.44	%		0.82	%		0.88	%		0.83	%(b)
Portfolio turnover(c)		5	%		9	%		10	%		14	%		18	%(a)

(a)	Not annualized.

(b)	Annualized.

(c)	Calculated at Fund level.

GREEN CENTURY MSCI INTERNATIONAL INDEX FUND INDIVIDUAL INVESTOR CLASS

FINANCIAL HIGHLIGHTS


	For the Years Ended July 31,
	2022			2021			2020			2019			2018
Net Asset Value, beginning of period	$	14.94		$	11.68		$	11.07		$	11.50		$	11.31

Income (loss) from investment operations:
Net investment income		0.19			0.09			0.10			0.18			0.17
Net realized and unrealized gain (loss) on investments		(2.87	)		3.27			0.59			(0.40	)		0.24

Total increase (decrease) from investment operations		(2.68	)		3.36			0.69			(0.22	)		0.41

Less dividends:
Dividends from net investment income		(0.18	)		(0.10	)		(0.08	)		(0.16	)		(0.19	)
Distributions from net realized gains		(0.26	)		—			—			(0.05	)		(0.03	)

Total decrease from dividends		(0.44	)		(0.10	)		(0.08	)		(0.21	)		(0.22	)

Net Asset Value, end of period	$	11.82		$	14.94		$	11.68		$	11.07		$	11.50

Total return		(18.36	)%		28.76	%		6.28	%		(1.82	)%		3.62	%
Ratios/Supplemental data:
Net assets, end of period (in 000’s)	$	47,435		$	46,508		$	29,073		$	22,110		$	18,744
Ratio of expenses to average net assets		1.28	%		1.28	%		1.28	%		1.28	%		1.28	%
Ratio of net investment income to average net assets		1.55	%		0.77	%		0.98	%		1.79	%		1.71	%
Portfolio turnover(a)		29	%		31	%		20	%		23	%		28	%

(a)	Calculated at Fund level.

GREEN CENTURY MSCI INTERNATIONAL INDEX FUND INSTITUTIONAL CLASS FINANCIAL HIGHLIGHTS


	For the Years Ended July 31,
	2022			2021			2020			2019			2018
Net Asset Value, beginning of period	$	14.90		$	11.66		$	11.07		$	11.50		$	11.31

Income (loss) from investment operations:
Net investment income		0.24			0.13			0.13			0.21			0.21
Net realized and unrealized gain (loss) on investments		(2.86	)		3.26			0.59			(0.38	)		0.23

Total increase (decrease) from investment operations		(2.62	)		3.39			0.72			(0.17	)		0.44

Less dividends:
Dividends from net investment income		(0.24	)		(0.15	)		(0.13	)		(0.21	)		(0.22	)
Distributions from net realized gains		(0.26	)		—			—			(0.05	)		(0.03	)

Total decrease from dividends		(0.50	)		(0.15	)		(0.13	)		(0.26	)		(0.25	)

Net Asset Value, end of period	$	11.78		$	14.90		$	11.66		$	11.07		$	11.50

Total return		(18.05	)%		29.09	%		6.51	%		(1.43	)%		3.90	%
Ratios/Supplemental data:
Net assets, end of period (in 000’s)	$	115,620		$	112,002		$	61,608		$	42,012		$	31,808
Ratio of expenses to average net assets		0.98	%		0.98	%		0.98	%		0.98	%		0.98	%
Ratio of net investment income to average net assets		1.85	%		1.07	%		1.28	%		2.09	%		2.01	%
Portfolio turnover(a)		29	%		31	%		20	%		23	%		28	%

(a)	Calculated at Fund level.

The Green Century Funds respect the privacy of our shareholders and customers. Our policy is to safeguard the personal information you have entrusted to us.

We collect nonpublic personal and financial information from you for the purpose of opening and maintaining a Green Century Funds shareholder account. The information we collect may include your name, address, Social Security Number, birth date, telephone number, email address, and/or bank account number. This information may come from your request for Green Century literature, your account registration forms, transactions in your account and other correspondence.

We do not sell any information about our current or former customers to third parties. Green Century may share your personal and financial information with third parties only:

•

When authorized by you.

•

As required or otherwise permitted by law.

•

To process transactions and service your account.

The third parties with whom we may share your personal and financial information, as described above, may include:

•

Affiliated and non-affiliated service providers (for example, the Funds’ Transfer Agent and printing and mailing providers who process transactions and service your account);

•

Government agencies, other regulatory bodies and law enforcement officials (for example, for tax purposes or for reporting suspicious transactions); and,

•

Other organizations, as permitted by law (for example, for fraud prevention).

Our contracts with service providers require them to maintain the confidentiality of your information.

Green Century restricts access to nonpublic personal and financial information about you to those employees who need to know that information in order to provide products or services to you. We require our employees to guard the confidentiality of your information and we maintain policies and procedures to safeguard your nonpublic personal and financial information.

Privacy Online. Just as we protect your personal and financial information collected on account registration forms and other correspondence, we also employ security measures to protect your information while you view your account or conduct transactions online. Our online account access website provides a secure platform to prevent unauthorized access to your information. Your Internet browser provides additional security by allowing us to use Secure Socket Layer (SSL) encryption up to 128-bit length encryption (the most secure system currently available) when transmitting your information. In an effort to provide the highest degree of security for your information, we strongly recommend the use of 128-bit encryption browsers. Versions of Mozilla 2.0 and higher, and Microsoft Internet Explorer 6.0 and higher provide this level of security.

Encryption is the process for scrambling your identification and account information as it passes between our system and your computer. The encryption process is built into most Internet browsers. The larger the number of bits for encryption (e.g. 40 or 128) the more difficult (exponentially) it is for an unauthorized person to unscramble the transmission. The highest level of encryption commercially available is 128-bit and is what we recommend to access your information.

Notice. Green Century will provide you notice of our Privacy Policy annually, as long as you maintain an account with us. Green Century reserves the right to make changes to this policy. We will notify you in writing before we make changes that affect the way we collect and share your information. If you have chosen to receive Green Century documents electronically, we will provide notification to you via email. We will notify you through periodic updates of our Privacy Policy online when we make changes that affect the security measures we employ to protect your information while viewing your account information or conducting transactions online.

Should you have questions, please telephone us at 1-800-934-7336.

This Privacy Policy applies to the Green Century Funds and Green Century Capital Management, Inc. (7/09)

The Green Century Funds Privacy Policy is not a part of the Prospectus.

INVESTMENT ADVISER AND ADMINISTRATOR

Green Century Capital Management, Inc.

114 State Street

Boston, MA 02109

1-800-934-7336

www.greencentury.com

email: [email protected]

INVESTMENT SUBADVISER (Balanced Fund)

Trillium Asset Management LLC

Two Financial Center

60 South Street, Suite 1100

Boston, MA 02111

INVESTMENT SUBADVISER (Equity Fund and International Index Fund)

Northern Trust Investments, Inc.

50 South LaSalle Street

Chicago, IL 60603

LICENSOR OF THE KLD400 EX FOSSIL FUELS INDEX (Equity Fund) AND THE WORLD EX USA SRI EX FOSSIL FUELS INDEX (International Index Fund)

MSCI Inc.

7 World Trade Center

250 Greenwich Street, 49^th Floor

New York, NY 10007

COUNSEL TO INDEPENDENT TRUSTEES OF THE FUNDS

Ropes & Gray LLP

Prudential Tower

800 Boylston Street

Boston, MA 02199

SUBADMINISTRATOR AND DISTRIBUTOR

UMB Fund Services, Inc. (Subadministrator)

UMB Distribution Services, LLC (Distributor)

235 West Galena Street

Milwaukee, WI 53212

CUSTODIAN

UMB Bank, n.a.

928 Grand Blvd

Kansas City, MO 64106

TRANSFER AGENT

Atlantic Shareholder Services, LLC

Three Canal Plaza

Portland, ME 04101

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

KPMG LLP

Two Financial Center

60 South Street

Boston, MA 02111

TO INVEST AND FOR ACCOUNT CORRESPONDENCE:

Green Century Funds

PO Box 588

Portland, ME 04112

1-800-221-5519

A Statement of Additional Information about the Funds has been filed with the Securities and Exchange Commission (SEC). The Statement of Additional Information, the independent registered public accounting firm’s report and financial statements in the Funds’ most recent annual report, and the financial statements in the Funds’ most recent semi-annual report, are incorporated by reference in this prospectus. Additional information about the Green Century Funds’ investments is available in the Funds’ annual and semi-annual reports. The annual report includes a discussion of the market conditions and investment strategies that significantly affected the Funds’ performance during their last fiscal year. To obtain free copies of any of these documents or to make shareholder inquiries, call 1-800-934-7336. Each of these documents is also available on our website at www.greencentury.com.

Fund reports, the Statement of Additional Information and other information about the Funds are also available on the EDGAR Database on the SEC’s internet site at http://www.sec.gov. Copies may be obtained upon payment of a duplicating fee, by electronic request at the following e-mail address: [email protected].

811-06351

Printed on recycled paper with soy-based ink.