Harbor Funds Prospectus

Prospectus

Harbor Funds

March 1, 2024

Harbor Funds	Retirement Class	Institutional Class	Administrative Class	Investor Class

Harbor Capital Appreciation Fund	HNACX	HACAX	HRCAX	HCAIX
Harbor Convertible Securities Fund	HNCVX	HACSX	HRCSX	HICSX
Harbor Core Bond Fund	HCBRX	HACBX	–	–
Harbor Core Plus Fund	HBFRX	HABDX	HRBDX	–
Harbor Disruptive Innovation Fund	HNMGX	HAMGX	HRMGX	HIMGX
Harbor Diversified International All Cap Fund	HNIDX	HAIDX	HRIDX	HIIDX
Harbor International Fund	HNINX	HAINX	HRINX	HIINX
Harbor International Compounders Fund	HNICX	HSICX	–	HVICX
Harbor International Core Fund	HAORX	HAOSX	HAOAX	HAONX
Harbor International Growth Fund	HNGFX	HAIGX	HRIGX	HIIGX
Harbor International Small Cap Fund	HNISX	HAISX	HRISX	HIISX
Harbor Large Cap Value Fund	HNLVX	HAVLX	HRLVX	HILVX
Harbor Mid Cap Fund	HMCRX	HMCLX	HMCDX	HMCNX
Harbor Mid Cap Value Fund	HNMVX	HAMVX	HRMVX	HIMVX
Harbor Small Cap Growth Fund	HNSGX	HASGX	HRSGX	HISGX
Harbor Small Cap Value Fund	HNVRX	HASCX	HSVRX	HISVX

The Securities and Exchange Commission (SEC) has not approved any Fund’s shares as an investment or determined whether this Prospectus is accurate or complete. Anyone who tells you otherwise is committing a crime.

Table of Contents

Fund Summaries
Harbor Capital Appreciation Fund	1
Harbor Convertible Securities Fund	5
Harbor Core Bond Fund	10
Harbor Core Plus Fund	14
Harbor Disruptive Innovation Fund	19
Harbor Diversified International All Cap Fund	24
Harbor International Fund	28
Harbor International Compounders Fund	32
Harbor International Core Fund	36
Harbor International Growth Fund	40
Harbor International Small Cap Fund	45
Harbor Large Cap Value Fund	49
Harbor Mid Cap Fund	53
Harbor Mid Cap Value Fund	56
Harbor Small Cap Growth Fund	60
Harbor Small Cap Value Fund	64
Additional Information about the Funds' Investments
Investment Objective	68
Investment Policies	68
Principal Investments	68
Non-Principal Investments	75
Portfolio Turnover	75
Portfolio Holdings Disclosure Policy	75
The Advisor
Harbor Capital Advisors, Inc.	76
Portfolio Management	78
The Subadvisors
Portfolio Management	79
Your Harbor Funds Account
Choosing a Share Class	96
Minimum Investment Exceptions	98
How to Purchase Shares	100
How to Exchange Shares	102
How to Sell Shares	104

Shareholder and Account Policies
Important Information About Opening an Account	106
Rights Reserved by Harbor Funds	106
Important Information Regarding State Escheatment Laws	106
Excessive Trading/Market-Timing	107
Shareholder Actions	108
Pricing of Fund Shares	108
Paying for Shares by Check	110
In-Kind Redemptions	110
Methods to Meet Redemption Requests	110
Accounts Below Share Class Minimums	110
Statements and Reports	110
Signature Guarantees	111
Dividends, Distributions and Taxes	112
Cost Basis	113
Investor Services
Online Services	114
Telephone Services	114
Retirement Accounts	114
Automatic Investment Plan	115
Automatic Exchange Plan	115
Automatic Withdrawal Plan	115
Dividend Exchange Plan	115
Financial Highlights	117
Financial Performance of the Fund	117
For More Information
Fund Details	148

Harbor Capital Appreciation Fund

Fund Summary

Investment Objective

The Fund seeks long-term growth of capital.

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 table and example below.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Retirement Class	Institutional Class	Administrative Class	Investor Class
Management Fees	0.60%	0.60%	0.60%	0.60%
Distribution and Service (12b-1) Fees	None	None	0.25%	0.25%
Other Expenses	0.04%	0.12%	0.12%	0.23%
Total Annual Fund Operating Expenses	0.64%	0.72%	0.97%	1.08%
Fee Waiver1	(0.04)%	(0.04)%	(0.04)%	(0.04)%
Total Annual Fund Operating Expenses After Fee Waiver1	0.60%	0.68%	0.93%	1.04%

1 The Advisor has contractually agreed to reduce the management fee to 0.56% on assets between $5 billion and $10 billion, 0.54% on assets between $10 billion and $20 billion and 0.53% on assets over $20 billion through February 28, 2025. Only the Fund’s Board of Trustees may modify or terminate this agreement.

Expense Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, under these assumptions, your costs would be:

	One Year	Three Years	Five Years	Ten Years
Retirement	$61	$201	$353	$795
Institutional	$69	$226	$397	$891
Administrative	$95	$305	$532	$1,186
Investor	$106	$340	$592	$1,314

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 may indicate higher transaction costs and may result in higher taxes when shares of the Fund are held in a taxable account. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Expense Example, do affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 27%.

Principal Investment Strategy

The Fund invests primarily in equity securities, principally common and preferred stocks, of U.S. companies with market capitalizations of at least $1 billion at the time of purchase and that the Subadvisor considers to have above average prospects for growth.

The Subadvisor uses a bottom-up approach, researching and evaluating individual companies, to manage the Fund’s portfolio. This research includes visits to companies and discussions with company management.

In selecting stocks for the Fund’s portfolio, the Subadvisor looks for companies that it believes have the following financial characteristics:

■

Superior absolute and relative earnings growth

■

Superior sales growth, improving sales momentum and high levels of unit growth

■

High or improving profitability

■

Strong balance sheets

In addition, the Subadvisor looks for companies that have actually achieved or exceeded expected earnings results and, in the opinion of the Subadvisor, are attractively valued relative to their growth prospects.

The Subadvisor focuses on stocks of companies that it believes have distinct attributes such as:

■

Strong market position with a defensible franchise

■

Unique marketing competence

■

Strong research and development leading to superior new product flow

■

Capable and disciplined management

The Subadvisor prefers companies that are in the early stages of demonstrating the above financial characteristics and other attributes.

The stocks of mid and large cap companies in the Fund’s portfolio are those the Subadvisor expects to maintain or achieve above average earnings growth. As part of its investment process, the Subadvisor considers environmental, social and governance (“ESG”) factors that it believes may have a material impact on an issuer and the value of its securities. As a result, the key ESG considerations may vary depending on the industry, sector, geographic region or other factors and the core business of each issuer. Sector allocations are the outcome of the Subadvisor’s bottom-up investment process and may, from time to time, result in more substantial investments in particular sectors.

The Fund may invest up to 20% of its total assets in the securities of foreign issuers, including issuers located or doing business in emerging markets.

Principal Risks

There is no guarantee that the investment objective of the Fund will be achieved. Stocks fluctuate in price and the value of your investment in the Fund may go down. This means that you could lose money on your investment in the Fund or the Fund may not perform as well as other investment options. Principal risks impacting the Fund (in alphabetical order after the first three risks) include:

Fund Summary

Harbor Capital Appreciation Fund

economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. They may also decline due to factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. Equity securities generally have greater price volatility than fixed income securities.

Growth Style Risk: Over time, a growth oriented investing style may go in and out of favor, which may cause the Fund to underperform other equity funds that use different investing styles.

Market Risk: Securities markets are volatile and can decline significantly in response to adverse market, economic, political, regulatory or other developments, which may lower the value of securities held by the Fund, sometimes rapidly or unpredictably. Events such as war, acts of terrorism, social unrest, natural disasters, recessions, inflation, rapid interest rate changes, supply chain disruptions, sanctions, the spread of infectious illness or other public health threats could also significantly impact the Fund and its investments.

Depositary Receipts Risk: Depositary receipts are certificates evidencing ownership of shares of a foreign issuer. These certificates are issued by depository banks and generally trade on an established market in the U.S. or elsewhere. The underlying shares are held in trust by a custodian bank or similar financial institution. The depository bank may not have physical custody of the underlying securities at all times and may charge fees for various services, including forwarding dividends and interest and corporate actions. Depositary receipts are alternatives to directly purchasing the underlying foreign securities in their national markets and currencies. Depositary receipts are subject to the risks associated with investing directly in foreign securities.

ESG Factors Risk: The consideration of ESG factors by the Subadvisor and/or Advisor, as applicable, could cause the Fund to perform differently than other funds. ESG factors are not the only consideration used by the Subadvisor and/or Advisor, as applicable, in making investment decisions for the Fund and the Fund may invest in a company that scores poorly on ESG factors if it scores well on other criteria. ESG factors may not be considered for every investment decision.

Foreign Securities Risk: Because the Fund may invest in securities of foreign issuers, an investment in the Fund is subject to special risks in addition to those of U.S. securities. These risks include heightened political and economic risks, greater volatility, currency fluctuations, higher transaction costs, delayed settlement, possible foreign controls on investment, possible sanctions by governmental bodies of other countries and less stringent investor protection and disclosure standards of foreign markets. Foreign securities are sometimes less liquid and harder to value than securities of U.S. issuers. These risks are more significant for issuers in emerging market countries. Global economies and financial markets are becoming increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market.

Issuer Risk: An adverse event affecting a particular issuer in which the Fund is invested, such as an unfavorable earnings report, may depress the value of that issuer’s stock, sometimes rapidly or unpredictably.

Large Cap Risk: Large cap stocks may fall out of favor relative to small or mid cap stocks, which may cause the Fund to underperform other equity funds that focus on small or mid cap stocks.

Mid Cap Risk: The Fund’s performance may be more volatile because it invests in mid cap stocks. Mid cap companies may have limited product lines, markets and financial resources. Securities of mid cap companies are usually less stable in price and less liquid than those of larger, more established companies. Additionally, mid cap stocks may fall out of favor relative to small or large cap stocks, which may cause the Fund to underperform other equity funds that focus on small or large cap stocks.

Preferred Stock Risk: Preferred stocks in which the Fund may invest are sensitive to interest rate changes, and are also subject to equity risk, which is the risk that stock prices will fall over short or extended periods of time. The rights of preferred stocks on the distribution of a company’s assets in the event of a liquidation are generally subordinate to the rights associated with a company’s debt securities.

Sector Risk: Because the Fund may, from time to time, be more heavily invested in particular sectors, the value of its shares may be especially sensitive to factors and economic risks that specifically affect those sectors. As a result, the Fund’s share price may fluctuate more widely than the value of shares of a mutual fund that invests in a broader range of sectors.

Selection Risk: The Subadvisor’s judgment about the attractiveness, value and growth potential of a particular security may be incorrect, which may cause the Fund to underperform. Additionally, the Subadvisor and/or Advisor, as applicable, potentially will be prevented from executing investment decisions at an advantageous time or price as a result of domestic or global market disruptions, particularly disruptions causing heightened market volatility and reduced market liquidity, as well as increased or changing regulations. Thus, investments that a Subadvisor and/or Advisor, as applicable, believes represent an attractive opportunity or in which the Fund seeks to obtain exposure may be unavailable entirely or in the specific quantities or prices sought by a Subadvisor and/or Advisor, as applicable, and the Fund may need to obtain the exposure through less advantageous or indirect investments or forgo the investment at the time.

Performance

The following bar chart and tables are intended to help you understand the risks and potential rewards of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Class has varied from one calendar year to another over the periods shown. The table shows how the Fund’s average annual total returns compare to a broad measure of market performance and an additional index over time. Please note that the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. To obtain updated performance information please visit the Fund’s website at harborcapital.com or call 800-422-1050.

Fund Summary

Harbor Capital Appreciation Fund

Calendar Year Total Returns for Institutional Class Shares

During the time periods shown in the bar chart, the Fund’s highest and lowest returns for a calendar quarter were:

	Total Returns	Quarter/Year
Best Quarter	34.29%	Q2 2020
Worst Quarter	-25.49%	Q2 2022

Average Annual Total Returns — As of December 31, 2023

	One Year	Annualized			Inception Date
	One Year	Five Years	Ten Years	Since Inception	Inception Date
Harbor Capital Appreciation Fund
Retirement Class* Before Taxes	53.86%	18.00%	14.10%	12.24%	03-01-2016
Institutional Class Before Taxes	53.74%	17.91%	14.04%	12.22%	12-29-1987
After Taxes on Distributions	53.74%	15.90%	12.02%	N/A
After Taxes on Distributions and Sale of Fund Shares	31.82%	14.35%	11.19%	N/A
Administrative Class Before Taxes	53.33%	17.62%	13.75%	11.57%	11-01-2002
Investor Class Before Taxes	53.20%	17.48%	13.62%	11.41%	11-01-2002
Comparative Indices (reflects no deduction for fees, expenses or taxes)
Russell 1000® Growth Index^	42.68%	19.50%	14.86%	11.30%
S&P 500 Index^^	26.29%	15.69%	12.03%	10.92%

Retirement Class shares commenced operations on March 1, 2016. The performance attributed to the Retirement Class shares prior to that date is that of the Institutional Class shares. Performance prior to March 1, 2016 has not been adjusted to reflect the lower expenses of Retirement Class shares. During this period, Retirement Class shares would have had returns similar to, but potentially higher than, Institutional Class shares due to the fact that Retirement Class shares represent interests in the same portfolio as Institutional Class shares but are subject to lower expenses.

Since Inception return based on the inception date of the Institutional Class shares. The Advisor considers this index to be representative of the Fund’s principal investment strategies and therefore the appropriate benchmark index for the Fund for performance comparison purposes.

^^Since Inception return based on the inception date of the Institutional Class shares. This index represents a broad measure of market performance.

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 will depend on a shareholder’s individual tax situation and may differ from those shown. The after-tax returns shown are not relevant to tax-exempt shareholders or shareholders who hold their Fund shares through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account. In some cases, average annual total return “After Taxes on Distributions and Sale of Fund Shares” may exceed the return “Before Taxes” and/or “After Taxes on Distributions” due to an assumed tax benefit for any losses on a sale of Fund shares at the end of the measurement period.After-tax returns are shown for Institutional Class shares only. After-tax returns for each of the Retirement, Administrative, and Investor Class of shares will vary.

Portfolio Management

Investment Advisor

Harbor Capital Advisors, Inc.

Subadvisor

Jennison Associates LLC (“Jennison”) has subadvised the Fund since May 1990.

Portfolio Managers

The co- portfolio managers are jointly and primarily responsible for the day-to-day investment decision making for the Fund.

Kathleen A. McCarragher

Jennison Associates LLC

Ms. McCarragher is a Director, Managing Director and the Head of Growth Equity of Jennison and has co-managed the Fund since 2013 and been involved in portfolio management for the Fund since 1998.

Blair A. Boyer

Jennison Associates LLC

Mr. Boyer is a Managing Director and the Co-Head of Large Cap Growth Equity of Jennison and has co-managed the Fund since 2019.

Fund Summary

Harbor Capital Appreciation Fund

Natasha Kuhlkin, CFA

Jennison Associates LLC

Ms. Kuhlkin is a Managing Director and a Large Cap Growth Equity Portfolio Manager of Jennison and has co-managed the Fund since 2019.

Buying and Selling Fund Shares

Shareholders may purchase or sell (redeem) Fund shares on any business day (normally any day the New York Stock Exchange is open). You may conduct transactions by mail, by telephone or through our website.

By Mail	Harbor Funds P.O. Box 804660 Chicago, IL 60680-4108
By Telephone	800-422-1050
By Visiting Our Website	harborcapital.com

Investors who wish to purchase, exchange or redeem shares held through a financial intermediary should contact the financial intermediary directly.

The minimum initial investment amounts are shown below. The minimums may be reduced or waived in some cases. There are no minimums for subsequent investments.

Type of Account	Retirement Class1	Institutional Class	Administrative Class2	Investor Class
Regular	$1,000,000	$50,000	$50,000	$2,500
Individual Retirement Account (IRA)	$1,000,000	$50,000	N/A	$1,000
Custodial (UGMA/UTMA)	$1,000,000	$50,000	N/A	$1,000

1 There is no minimum investment for (1) employer-sponsored group retirement or benefit plans (with more than one participant) that maintain accounts with Harbor Funds at an omnibus or plan level, including: (i) plans established under Internal Revenue Code Sections 401(a), 403(b) or 457, (ii) profit-sharing plans, cash balance plans and money purchase pension plans, (iii) non-qualified deferred compensation plans, and (iv) retiree health benefit plans; and (2) certain wrap or model-driven asset allocation program accounts for the benefit of clients of financial intermediaries, as approved by the Distributor.

2 Limited only to employer-sponsored retirement or benefit plans and financial intermediaries. There is no minimum investment for employer-sponsored retirement or benefit plans.

Tax Information

Distributions you receive from the Fund are subject to federal income tax and may also be subject to state and local taxes. These distributions will generally be taxed as ordinary income or capital gains, unless you are investing through a tax-deferred retirement account, such as a 401(k) plan or individual retirement account. Investments in tax-deferred accounts may be subject to tax when they are withdrawn.

Payments to Broker-Dealers and Other Financial Intermediaries

The Fund, the Advisor and/or its related companies have in the past and could in the future pay intermediaries, which may include banks, broker-dealers, or financial professionals, for marketing activities and presentations, educational training programs, conferences, the development of technology platforms and reporting systems and data or other services related to 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 sales representative to recommend the Fund over another investment. Ask your sales representative or visit your financial intermediary’s website for more information.

Harbor Convertible Securities Fund

Fund Summary

Investment Objective

The Fund seeks to maximize total returns (i.e., current income and capital appreciation).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Retirement Class	Institutional Class	Administrative Class	Investor Class
Management Fees1	0.50%	0.50%	0.50%	0.50%
Distribution and Service (12b-1) Fees	None	None	0.25%	0.25%
Other Expenses1	0.50%	0.58%	0.58%	0.69%
Total Annual Fund Operating Expenses	1.00%	1.08%	1.33%	1.44%
Expense Reimbursement2	(0.37)%	(0.37)%	(0.37)%	(0.37)%
Total Annual Fund Operating Expenses After Expense Reimbursement2	0.63%	0.71%	0.96%	1.07%

1 Restated to reflect current fees.

2 The Advisor has contractually agreed to limit the Fund’s operating expenses, excluding interest expense (if any), to 0.63%, 0.71%, 0.96%, and 1.07% for the Retirement Class, Institutional Class, Administrative Class, and Investor Class, respectively, through February 28, 2025. Only the Fund’s Board of Trustees may modify or terminate these agreements.

Expense Example

	One Year	Three Years	Five Years	Ten Years
Retirement	$64	$282	$516	$1,191
Institutional	$73	$307	$560	$1,284
Administrative	$98	$385	$693	$1,569
Investor	$109	$419	$752	$1,692

Portfolio Turnover

Principal Investment Strategy

Under normal market conditions, the Fund invests at least 80% of its net assets, plus borrowings for investment purposes, in a diversified portfolio of convertible securities.

Convertible securities are “hybrid” securities that possess both fixed income and equity characteristics. These convertible securities include corporate bonds; and preferred stocks that are convertible into common stock or its equivalent value. A convertible security generally performs more like a common stock when the price of the underlying stock is closer to or above the conversion price because it is more likely that the convertible security will be converted into stock. A convertible security generally performs more like a bond when the price of the underlying stock is well below the conversion price because it is more likely that the convertible security will mature without being converted. While the Fund has broad discretion to invest in all types of convertible securities, the Fund primarily invests in convertible bonds, which may be unrated, or may have ratings assigned by credit rating agencies, including below investment-grade ratings (known as “junk bonds”). To assess the quality of unrated securities, the Subadviser evaluates an issuer’s probability of default using a proprietary default probability model that considers multiple variables, including capital structure of the firm, asset volatility, and annual cash outflows of interest and dividend payments. The Fund invests primarily in U.S. dollar denominated securities, including those of foreign issuers; however, the Fund may invest in securities denominated in other currencies.

The Subadvisor follows a structured investment process based on the testing of investment hypotheses using historical data. The Subadvisor’s investment process utilizes proprietary quantitative models to produce investment recommendations. The Subadvisor’s portfolio management team retains discretion with respect to all investment decisions. The Subadvisor generates proprietary insights based on its experience and reasoned intuition to form an investment hypothesis. Insights are a means to express isolated drivers of returns that the Subadvisor believes are likely to generate excess returns over time.

Using historical market data, the Subadvisor back-tests each investment hypothesis to determine whether actual observations appear consistent with the hypothesis over time. Insights are weighted in the Subadvisor’s models according to their deemed strength in predicting returns, as determined by the Subadvisor through this testing process. In managing the Fund, the Subadvisor will rely on insights that seek to target company specific risk, which form the basis of security selection decisions and assess metrics such as company strength, company outlook, and valuation. The Subadvisor’s models consider data from multiple sources, including issuer specific information such as company cash flow, default risk, earnings expectations, and price volatility.

As part of its investment process with respect to each portfolio investment, the Subadvisor considers environmental, social and governance (“ESG”) factors that it believes may have a material impact on an issuer and the value of its securities. As a result, the key ESG considerations may vary depending on the industry, sector, geographic region or other factors and the core business of each issuer.

The Subadvisor expects that the majority of the Fund’s total returns will be generated from security selection of convertible securities. The Subadvisor’s optimization process seeks to maximize total returns while minimizing expected risk and transaction costs. The Subadvisor measures risk at the portfolio level and on each instrument. The Subadvisor conducts performance measurement

Fund Summary

Harbor Convertible Securities Fund

and risk analysis to seek to validate the accuracy of the investment process with the aim of achieving continuous improvement over time.

Duration/Maturity: Although duration may be one of the characteristics considered in security selection, the Fund does not focus on securities with any particular duration or maturity and does not seek to maintain the maturity of the Fund’s portfolio in any particular range.

Credit Quality: The Fund invests primarily in convertible securities, which may be unrated, or may have ratings assigned by credit rating agencies, including below investment-grade ratings. The Subadvisor does not target a given weighted average portfolio quality; this varies from time to time, depending on the level of assets allocated to such securities.

Principal Risks

There is no guarantee that the investment objective of the Fund will be achieved. Convertible securities fluctuate in price in response to various factors, including changes in interest rates, changes in the price of equity securities, changes in market conditions and issuer-specific events, and the value of your investment in the Fund may go down. This means that you could lose money on your investment in the Fund or the Fund may not perform as well as other possible investments. Principal risks impacting the Fund (in alphabetical order after the first four risks) include:

Convertible Securities Risk: Convertible securities have investment characteristics of both equity and debt securities. Investments in convertible securities are subject to risks associated with debt instruments, including interest rate and credit risk. The values of convertible securities also react to changes in the value of the common stock into which they convert, and are thus subject to many of the same risks as investing in common stock. Convertible securities generally tend to be of lower credit quality. A convertible security may also be subject to redemption at the option of the issuer at a price established in the convertible security’s governing instrument. If a convertible security held by the Fund is called for redemption, the Fund will be required to permit the issuer to redeem the security, convert it into the underlying common stock or sell it to a third party, which could result in a loss to the Fund. Additionally, the Fund could lose money if the issuer of a convertible security is unable to meet its financial obligations or declares bankruptcy.

Quantitative Analysis Risk: There are limitations inherent in every quantitative model. The value of securities selected using quantitative analysis can react differently to issuer, political, market, and economic developments than the market as a whole or securities selected using only fundamental analysis. The factors used in quantitative analysis and the weight placed on those factors may not be predictive of a security’s value. In addition, historical trends in data may not be predictive going forward. The strategies and techniques employed in a quantitative model cannot fully match the complexity of the financial markets and therefore sudden unanticipated changes in underlying market conditions can significantly impact their performance. The effectiveness of the

given strategy or technique may deteriorate in an unpredictable fashion for any number of reasons including, but not limited to, an increase in the amount of assets managed or the use of similar strategies or techniques by other market participants and/or market dynamic shifts over time. In addition, factors that affect a security’s value can change over time, and these changes may not be reflected in the quantitative model. Any model may contain flaws the existence and effect of which may be discovered only after the fact or not at all. There can be no assurances that the strategies pursued or the techniques implemented in the quantitative model will be profitable, and various market conditions may be materially less favorable to certain strategies than others. Even in the absence of flaws, a model may not perform as anticipated.

Credit Risk: The issuer or guarantor of a security owned by the Fund could default on its obligation to pay principal or interest or its credit rating could be downgraded. Convertible securities are generally junior to the company’s non-convertible debt so the company would normally have to pay interest on its nonconvertible debt before interest can be paid on the convertible securities. Credit risk may be higher for the Fund because it invests primarily in convertible securities of companies with debt rated below investment-grade.

High Portfolio Turnover Risk: Higher portfolio turnover may adversely affect Fund performance by increasing Fund transaction costs and may lead to the realization and distribution to shareholders of higher capital gains, which may increase a shareholder’s tax liability.

High-Yield Risk: There is a greater risk that the Fund will lose money because it invests primarily in below investment-grade convertible securities and unrated securities of similar credit quality (commonly referred to as “high-yield” or “junk” bonds). These securities are considered speculative because they have a higher risk of issuer default, are subject to greater price volatility and may be illiquid.

Interest Rate Risk: As interest rates rise, the values of convertible securities held by the Fund are likely to decrease and reduce the value of the Fund’s portfolio. Convertible securities are normally much more sensitive to interest rate changes when they are valued more like the company’s bonds than the company’s common stock, such as when the conversion price for the convertible security is well above the common stock price. Rising interest rates may

Fund Summary

Harbor Convertible Securities Fund

lead to increased redemptions, increased volatility and decreased liquidity in the fixed income markets, making it more difficult for the Fund to sell its convertible securities when the Subadvisor may wish to sell or must sell to meet redemptions. During periods when interest rates are low or there are negative interest rates, the Fund’s yield (and total return) also may be low or the Fund may be unable to maintain positive returns or minimize the volatility of the Fund’s net asset value per share. Changing interest rates may have unpredictable effects on the markets, may result in heightened market volatility and may detract from Fund performance. In addition, changes in monetary policy may exacerbate the risks associated with changing interest rates.

Liquidity Risk: The market for convertible securities is less liquid than the market for non-convertible corporate bonds. The Fund may at times have greater difficulty buying or selling specific convertible securities at prices the Subadvisor believes are reasonable, which would be adverse to the Fund. Valuation of investments may be difficult, particularly during periods of market volatility or reduced liquidity and for investments that trade infrequently or irregularly. In these circumstances, among others, an investment may be valued using fair value methodologies that are inherently subjective and reflect good faith judgments based on available information.

Performance

Effective March 1, 2023, BlueCove Limited (“BlueCove”) became the Fund’s Subadvisor. Performance prior to that date is not attributable to BlueCove.

The following bar chart and tables are intended to help you understand the risks and potential rewards of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Class has varied from one calendar year to another over the periods shown. The table shows how the Fund’s average annual total returns of the share classes presented compare to a broad measure of market performance and an additional index over time. Please note that the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. To obtain updated performance information please visit the Fund’s website at harborcapital.com or call 800-422-1050.

Calendar Year Total Returns for Institutional Class Shares

During the time periods shown in the bar chart, the Fund’s highest and lowest returns for a calendar quarter were:

	Total Returns	Quarter/Year
Best Quarter	23.06%	Q2 2020
Worst Quarter	-13.17%	Q1 2020

Fund Summary

Harbor Convertible Securities Fund

Average Annual Total Returns — As of December 31, 2023

	One Year	Annualized			Inception Date
	One Year	Five Years	Ten Years	Since Inception	Inception Date
Harbor Convertible Securities Fund
Retirement Class* Before Taxes	10.84%	8.55%	5.82%	5.90%	03-01-2016
Institutional Class Before Taxes	10.65%	8.42%	5.74%	5.84%	05-01-2011
After Taxes on Distributions	9.37%	6.15%	3.53%	N/A
After Taxes on Distributions and Sale of Fund Shares	6.36%	5.85%	3.62%	N/A
Administrative Class Before Taxes	10.03%	8.09%	5.42%	5.53%	05-01-2011
Investor Class Before Taxes	10.35%	8.06%	5.37%	5.46%	05-01-2011
Comparative Indices (reflects no deduction for fees, expenses or taxes)
ICE BofA U.S. Convertible Bond Index^	12.87%	11.93%	8.90%	9.01%
Bloomberg U.S. Aggregate Bond Index^^	5.53%	1.10%	1.81%	2.06%

^^Since Inception return based on the inception date of the Institutional Class shares. This index represents a broad measure of market performance and has been added to comply with new regulatory requirements.

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 will depend on a shareholder’s individual tax situation and may differ from those shown. The after-tax returns shown are not relevant to tax-exempt shareholders or shareholders who hold their Fund shares through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account. In some cases, average annual total return “After Taxes on Distributions and Sale of Fund Shares” may exceed the return “Before Taxes” and/or “After Taxes on Distributions” due to an assumed tax benefit for any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown for Institutional Class shares only. After-tax returns for each of the Retirement, Administrative, and Investor Class of shares will vary.

Portfolio Management

Investment Advisor

Harbor Capital Advisors, Inc.

Subadvisor

BlueCove Limited (“BlueCove”) has subadvised the Fund since March 2023.

Portfolio Managers

BlueCove employs a team approach in which a number of portfolio management individuals will be involved in the day-to-day investment decision making of the Fund. Mr. Brodsky, Mr. Harper and Mr. Thomas are jointly responsible for managing the Fund.

Benjamin Brodsky, CFA

BlueCove Limited

Mr. Brodsky is Chief Investment Officer of BlueCove and has managed the Fund since 2023.

Michael Harper, CFA

BlueCove Limited

Mr. Harper is Head of Portfolio Management of BlueCove and has managed the Fund since 2023.

Benoy Thomas, CFA

BlueCove Limited

Mr. Thomas is Head of Credit of BlueCove and has managed the Fund since 2023.

Fund Summary

Harbor Convertible Securities Fund

Buying and Selling Fund Shares

By Mail	Harbor Funds P.O. Box 804660 Chicago, IL 60680-4108
By Telephone	800-422-1050
By Visiting Our Website	harborcapital.com

Investors who wish to purchase, exchange or redeem shares held through a financial intermediary should contact the financial intermediary directly.

The minimum initial investment amounts are shown below. The minimums may be reduced or waived in some cases. There are no minimums for subsequent investments.

Type of Account	Retirement Class1	Institutional Class	Administrative Class2	Investor Class
Regular	$1,000,000	$1,000	$50,000	$2,500
Individual Retirement Account (IRA)	$1,000,000	$1,000	N/A	$1,000
Custodial (UGMA/UTMA)	$1,000,000	$1,000	N/A	$1,000

2 Limited only to employer-sponsored retirement or benefit plans and financial intermediaries. There is no minimum investment for employer-sponsored retirement or benefit plans.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Harbor Core Bond Fund

Fund Summary

Investment Objective

The Fund seeks total return.

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Retirement Class	Institutional Class
Management Fees	0.23%	0.23%
Distribution and Service (12b-1) Fees	None	None
Other Expenses	0.13%	0.21%
Total Annual Fund Operating Expenses	0.36%	0.44%
Expense Reimbursement1	(0.10)%	(0.10)%
Total Annual Fund Operating Expenses After Expense Reimbursement1	0.26%	0.34%

1 The Advisor has contractually agreed to limit the Fund’s operating expenses, excluding interest expense (if any), to 0.26% and 0.34% for the Retirement Class and Institutional Class, respectively, through February 28, 2025. Only the Fund’s Board of Trustees may modify or terminate this agreement.

Expense Example

	One Year	Three Years	Five Years	Ten Years
Retirement	$27	$106	$192	$446
Institutional	$35	$131	$236	$545

Portfolio Turnover

Principal Investment Strategy

The Fund invests primarily in investment-grade fixed income securities of issuers located in the U.S. Under normal market conditions, the Fund invests at least 80% of its net assets, plus borrowings for investment purposes, in a diversified portfolio of fixed income instruments. Fixed income instruments include bonds, debt securities and other similar instruments issued by various public- or private-sector entities.

The Subadvisor’s approach is grounded in detailed bottom-up research and emphasizes careful security selection through:

■

Rigorous fundamental credit analysis of the issuer,

■

A detailed review of the structural features of the security, and

■

Relative-value comparisons to other opportunities.

In order to be selected for the portfolio, a security must be attractive with respect to all three of these factors. If one factor deteriorates, the security becomes a candidate for sale.

When forming an opinion on the creditworthiness of an issuer, the Subadvisor evaluates many factors, including financial performance, balance sheet strength, management quality, operating risk, market position, industry fundamentals, event risk, and economic sensitivity. The Subadvisor’s analysis also includes a detailed review of the underlying structural features of a bond, such as coupon type, redemption features, level of subordination, and collateral. For securitized bonds (such as mortgage-backed and asset-backed), the Subadvisor assesses factors such as issue sponsorship, structure, deal history, regulation, and liquidity. The Subadvisor also evaluates issuers with respect to environmental, social and governance (“ESG”) factors and integrates consideration of these factors into its investment process. The key ESG considerations may vary depending on the industry, sector, geographic region or other factors and the core business of each issuer. The ESG criteria utilized by the Subadvisor is only one factor among others considered in the investment process.

The Subadvisor believes that it is difficult to predict the timing, direction, and magnitude of future interest-rate changes. Therefore, duration management and yield-curve positioning are not part of the Fund’s strategy.

The portfolio is constructed from the bottom up and is comprised of U.S. dollar-denominated securities. The Subadvisor sets sector allocations based on its views of relative values between sectors and opportunities at the security level. A comprehensive risk overlay also influences portfolio construction. The Subadvisor systematically measures and monitors the Fund’s key risk exposures. The overall aim of the portfolio construction process is to craft a portfolio of attractively priced securities (relative to other opportunities in the universe) that when combined together in a portfolio provide what the Subadvisor believes will be attractive expected return, reasonable risk exposures, and adequate liquidity.

At times, the Fund may invest a large percentage of its assets in investment-grade mortgage-backed and asset-backed securities.

Credit Quality: The Fund invests primarily in investment-grade securities.

Duration: The Fund’s average duration, as calculated by the Subadvisor, is normally equal to that of its benchmark, plus or minus 10%. The duration of the Bloomberg U.S. Aggregate Bond Index as of December 31, 2023 was 6.24 years. Average duration is a weighted average of all bond durations in the Fund’s portfolio, and is an approximate measure of the sensitivity of the market

Fund Summary

Harbor Core Bond Fund

value of the Fund’s holdings to changes in interest rates. If the Fund’s duration is longer than the market’s duration, the Fund would be expected to experience a greater change in the value of its assets when interest rates are rising or falling than would the market as a whole.

Principal Risks

There is no guarantee that the investment objective of the Fund will be achieved. Fixed income securities fluctuate in price in response to various factors, including changes in interest rates, changes in market conditions and issuer-specific events, and the value of your investment in the Fund may go down. This means that you could lose money on your investment in the Fund or the Fund may not perform as well as other possible investments. Principal risks impacting the Fund (in alphabetical order after the first four risks) include:

Interest Rate Risk: As interest rates rise, the values of fixed income securities held by the Fund are likely to decrease and reduce the value of the Fund’s portfolio. Securities with longer durations tend to be more sensitive to changes in interest rates and are usually more volatile than securities with shorter durations. For example, a 5 year average duration generally means the price of a fixed income security will decrease in value by 5% if interest rates rise by 1%. Rising interest rates may lead to increased redemptions, increased volatility and decreased liquidity in the fixed income markets, making it more difficult for the Fund to sell its fixed income securities when the Subadvisor may wish to sell or must sell to meet redemptions. During periods when interest rates are low or there are negative interest rates, the Fund’s yield (and total return) also may be low or the Fund may be unable to maintain positive returns or minimize the volatility of the Fund’s net asset value per share. Changing interest rates may have unpredictable effects on the markets, may result in heightened market volatility and may detract from Fund performance. In addition, changes in monetary policy may exacerbate the risks associated with changing interest rates.

Credit Risk: The issuer or guarantor of a security owned by the Fund could default on its obligation to pay principal or interest or its credit rating could be downgraded. Likewise, a counterparty to a contractual instrument owned by the Fund could default on its obligation.

Mortgage- and Asset-Backed Securities Risk: Mortgage and other asset-backed securities in the Fund’s portfolio may have especially volatile prices because the embedded leverage can magnify the impact of the extension or contraction event on the underlying cash flow. Mortgage-related securities are also subject to prepayment and extension risks.

if it scores well on other criteria. ESG factors may not be considered for every investment decision.

Extension Risk: When interest rates are rising, certain callable fixed income securities may be extended because of slower than expected principal payments. This would lock in a below-market interest rate, increase the security’s duration and reduce the value of the security.

Liquidity Risk: A particular investment may be difficult to purchase or sell and the Fund may be unable to sell illiquid securities at an advantageous time or price or achieve its desired level of exposure to a certain sector. Liquidity risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income mutual funds may be higher than normal, causing increased supply in the market due to selling activity. Valuation of investments may be difficult, particularly during periods of market volatility or reduced liquidity and for investments that trade infrequently or irregularly. In these circumstances, among others, an investment may be valued using fair value methodologies that are inherently subjective and reflect good faith judgments based on available information.

Prepayment Risk: When interest rates are declining, the issuer of a fixed income security, including a pass-through security such as a mortgage-backed or an asset-backed security, may exercise its option to prepay principal earlier than scheduled, forcing the Fund to reinvest in lower yielding securities.

U.S. Government Securities Risk: Securities issued or guaranteed by U.S. government agencies or government-sponsored entities may not be backed by the full faith and credit of the U.S. government. As a result, no assurance can be given that the U.S. government will provide financial support to these securities or issuers (such as securities issued by the Federal National Mortgage Association, or the Federal Home Loan Mortgage Corporation). Although certain government securities are backed by the full faith and credit of the U.S. government (such as securities issued by the Government National Mortgage Association), circumstances could arise that would delay or prevent the payment of interest or principal. It is possible that issuers of U.S. government securities will not have the funds to meet their payment obligations in the future and, in these circumstances, the Fund’s returns may be adversely affected.

Fund Summary

Harbor Core Bond Fund

Performance

The following bar chart and tables are intended to help you understand the risks and potential rewards of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Class has varied from one calendar year to another over the periods shown. The table shows how the Fund’s average annual total returns of the share classes presented compared to the returns of the Fund’s benchmark index, which includes securities with investment characteristics similar to those held by the Fund. Please note that the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. To obtain updated performance information please visit the Fund’s website at harborcapital.com or call 800-422-1050.

Calendar Year Total Returns for Institutional Class Shares

During the time periods shown in the bar chart, the Fund’s highest and lowest returns for a calendar quarter were:

	Total Returns	Quarter/Year
Best Quarter	6.53%	Q4 2023
Worst Quarter	-5.96%	Q1 2022

Average Annual Total Returns — As of December 31, 2023

	One Year	Annualized			Inception Date
	One Year	Five Years	Ten Years	Since Inception	Inception Date
Harbor Core Bond Fund
Retirement Class Before Taxes	5.81%	1.39%	N/A	1.49%	06-01-2018
Institutional Class Before Taxes	5.73%	1.31%	N/A	1.41%	06-01-2018
After Taxes on Distributions	4.07%	-0.02%	N/A	0.09%
After Taxes on Distributions and Sale of Fund Shares	3.36%	0.50%	N/A	0.58%
Comparative Index (reflects no deduction for fees, expenses or taxes)
Bloomberg U.S. Aggregate Bond Index^	5.53%	1.10%	N/A	1.26%

Since Inception return based on the inception date of the Institutional Class shares.

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 will depend on a shareholder’s individual tax situation and may differ from those shown. The after-tax returns shown are not relevant to tax-exempt shareholders or shareholders who hold their Fund shares through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account. In some cases, average annual total return “After Taxes on Distributions and Sale of Fund Shares” may exceed the return “Before Taxes” and/or “After Taxes on Distributions” due to an assumed tax benefit for any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown for Institutional Class shares only. After-tax returns for the Retirement Class of shares will vary.

Portfolio Management

Investment Advisor

Harbor Capital Advisors, Inc.

Subadvisor

Income Research + Management (“IR+M”) has subadvised the Fund since 2018.

Portfolio Managers

The portfolio managers are jointly and primarily responsible for the day-to-day investment decision making for the Fund.

William A. O’Malley, CFA

Income Research + Management

Mr. O’Malley is a Managing Principal, Senior Portfolio Manager, and Director of Investment Team at IR+M and has served as a portfolio manager for the Fund since 2018.

James E. Gubitosi, CFA

Income Research + Management

Mr. Gubitosi is a Co-Chief Investment Officer at IR+M and has served as a portfolio manager for the Fund since 2018.

Bill O’Neill, CFA

Income Research + Management

Mr. O’Neill is a Senior Portfolio Manager at IR+M and has served as a portfolio manager for the Fund since 2018.

Fund Summary

Harbor Core Bond Fund

Jake Remley, CFA

Income Research + Management

Mr. Remley is a Senior Portfolio Manager at IR+M and has served as a portfolio manager for the Fund since 2018.

Matt Walker, CFA

Income Research + Management

Mr. Walker is a Senior Portfolio Manager at IR+M and has served as a portfolio manager for the Fund since 2018.

Rachel Campbell, CFA

Income Research + Management

Ms. Campbell is a Portfolio Manager and the Director of Securitized Research at IR+M and has served as a portfolio manager for the Fund since 2018.

Buying and Selling Fund Shares

By Mail	Harbor Funds P.O. Box 804660 Chicago, IL 60680-4108
By Telephone	800-422-1050
By Visiting Our Website	harborcapital.com

Investors who wish to purchase, exchange or redeem shares held through a financial intermediary should contact the financial intermediary directly.

The minimum initial investment amounts are shown below. The minimums may be reduced or waived in some cases. There are no minimums for subsequent investments.

Type of Account	Retirement Class1	Institutional Class
Regular	$1,000,000	$1,000
Individual Retirement Account (IRA)	$1,000,000	$1,000
Custodial (UGMA/UTMA)	$1,000,000	$1,000

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Harbor Core Plus Fund

Fund Summary

Investment Objective

The Fund seeks total return.

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Retirement Class	Institutional Class	Administrative Class
Management Fees	0.25%	0.25%	0.25%
Distribution and Service (12b-1) Fees	None	None	0.25%
Other Expenses	0.05%	0.13%	0.13%
Total Annual Fund Operating Expenses1	0.30%	0.38%	0.63%

1 The Advisor has contractually agreed to limit the Fund’s operating expenses, excluding interest expense (if any), to 0.30%, 0.38%, and 0.63% for the Retirement Class, Institutional Class, and Administrative Class, respectively, through February 28, 2025. Only the Fund’s Board of Trustees may modify or terminate this agreement.

Expense Example

	One Year	Three Years	Five Years	Ten Years
Retirement	$31	$97	$169	$381
Institutional	$39	$122	$213	$480
Administrative	$64	$202	$351	$786

Portfolio Turnover

Principal Investment Strategy

The Fund invests primarily in U.S. dollar denominated fixed income securities. Under normal market conditions, the Fund invests at least 80% of its net assets, plus borrowings for investment purposes, in a diversified portfolio of fixed income instruments. Fixed income instruments include, but are not limited to: obligations issued or guaranteed by the U.S. Government, its agencies, or instrumentalities; corporate debt securities; municipal debt

securities; U.S. dollar-denominated debt of foreign issuers; and securitized securities including mortgage-backed and asset-backed securities, which may also include non-agency mortgage-backed securities. These securities may have different types of interest rate payment and reset terms.

The Subadvisor’s approach is grounded in detailed bottom-up research and emphasizes careful security selection through:

■

Rigorous fundamental credit analysis of the issuer;

■

A detailed review of the structural features of the security; and

■

Relative-value comparisons to other opportunities.

In order to be selected for the portfolio, a security must be attractive with respect to all three of these factors. If one factor deteriorates, the security becomes a candidate for sale.

The Subadvisor also evaluates issuers with respect to environmental, social and governance (“ESG”) factors and integrates consideration of these factors into its investment process. The key ESG considerations may vary depending on the industry, sector, geographic region or other factors and the core business of each issuer. The ESG criteria utilized by the Subadvisor is only one factor among others considered in the investment process.

Credit Quality: The Fund invests primarily in investment-grade securities, but may invest up to 25% of its total assets in below investment-grade securities, commonly referred to as “high-yield” or “junk” bonds, as rated by Moody’s Investor Service, Inc., Standard & Poor’s Rating Services or Fitch, Inc., or, if unrated, as determined by the Fund’s Subadvisor.

Duration: The Fund’s average duration, as calculated by the Subadvisor, is normally equal to that of its benchmark, plus or minus 0.5 years. The duration of the Bloomberg U.S. Aggregate Bond Index as of December 31, 2023 was 6.24 years. Average duration is a weighted average of all bond durations in the Fund’s portfolio, and is an approximate measure of the sensitivity of the market value of the Fund’s holdings to changes in interest rates. If the Fund’s duration is longer than the market’s duration, the Fund would be expected to experience a greater change in the

Fund Summary

Harbor Core Plus Fund

value of its assets when interest rates are rising or falling than would the market as a whole.

Principal Risks

Credit Risk: The issuer or guarantor of a security owned by the Fund could default on its obligation to pay principal or interest or its credit rating could be downgraded. Likewise, a counterparty to a derivative or other contractual instrument owned by the Fund could default on its obligation. This risk may be higher for below investment-grade securities.

High-Yield Risk: There is a greater risk that the Fund will lose money because it invests in below investment-grade fixed income securities and unrated securities of similar credit quality (commonly referred to as “high-yield” or “junk” bonds). These securities are considered speculative because they have a higher risk of issuer default, are subject to greater price volatility and may be illiquid.

of convertible securities also react to changes in the value of the common stock into which they convert, and are thus subject to many of the same risks as investing in common stock. Convertible securities generally tend to be of lower credit quality. A convertible security may also be subject to redemption at the option of the issuer at a price established in the convertible security’s governing instrument. If a convertible security held by the Fund is called for redemption, the Fund will be required to permit the issuer to redeem the security, convert it into the underlying common stock or sell it to a third party, which could result in a loss to the Fund. Additionally, the Fund could lose money if the issuer of a convertible security is unable to meet its financial obligations or declares bankruptcy.

Municipal Risk: Municipal securities are debt issues of governmental bodies, other than the U.S. Government, within the United States, including securities issued by or on behalf of states, territories, and possessions of the United States, by the District of Columbia, and by political subdivisions and their duly constituted agencies and instrumentalities. Municipal securities are subject to the risk that legislative changes and local and business developments may adversely affect the yield or value of the Fund’s investments in such securities. In addition, in order to be tax-exempt, municipal securities must meet certain legal requirements. Failure to meet such requirements may cause the interest received by the Fund on the municipal securities to be taxable. The interest on these issues generally is not included in “gross income” for regular federal income tax purposes, subject, however, to many exceptions and limitations. Legislation to restrict or eliminate the federal income tax exemption for interest on municipal securities has, from time to time, been introduced before Congress. If such a proposal were enacted, the availability of municipal securities for investment by the Fund could be adversely affected.

Fund Summary

Harbor Core Plus Fund

Preferred Securities Risk: Preferred securities combine some of the characteristics of both common stocks and bonds. Preferred securities are typically subordinated to bonds and other debt securities in a company’s capital structure in terms of priority to corporate income, subjecting them to greater credit risk than those debt securities. Generally, holders of preferred securities have no voting rights with respect to the issuing company unless preferred dividends have been in arrears for a specified number of periods, at which time the preferred security holders may obtain limited rights. In certain circumstances, an issuer of preferred securities may defer payment on the securities and, in some cases, redeem the securities prior to a specified date. Preferred securities may also be substantially less liquid than other securities, including common stock.

Performance

Effective February 2, 2022, IR+M became the Fund’s Subadvisor. Performance prior to that date is not attributable to IR+M.

The following bar chart and tables are intended to help you understand the risks and potential rewards of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Class has varied from one calendar year to another over the periods shown. The table shows how the Fund’s average annual total returns of the share classes presented compared to the returns of the Fund’s benchmark index, which includes securities with investment characteristics similar to those held by the Fund. Please note that the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. To obtain updated performance information please visit the Fund’s website at harborcapital.com or call 800-422-1050.

Calendar Year Total Returns for Institutional Class Shares

During the time periods shown in the bar chart, the Fund’s highest and lowest returns for a calendar quarter were:

	Total Returns	Quarter/Year
Best Quarter	6.76%	Q4 2023
Worst Quarter	-5.74%	Q1 2022

Fund Summary

Harbor Core Plus Fund

Average Annual Total Returns — As of December 31, 2023

	One Year	Annualized			Inception Date
	One Year	Five Years	Ten Years	Since Inception	Inception Date
Harbor Core Plus Fund
Retirement Class* Before Taxes	6.78%	1.78%	2.17%	6.09%	06-01-2018
Institutional Class Before Taxes	6.70%	1.66%	2.11%	6.08%	12-29-1987
After Taxes on Distributions	4.85%	0.26%	0.57%	N/A
After Taxes on Distributions and Sale of Fund Shares	3.93%	0.70%	0.95%	N/A
Administrative Class Before Taxes	6.43%	1.41%	1.86%	3.76%	11-01-2002
Comparative Index (reflects no deduction for fees, expenses or taxes)
Bloomberg U.S. Aggregate Bond Index^	5.53%	1.10%	1.81%	5.44%

Retirement Class shares commenced operations on June 1, 2018. The performance attributed to the Retirement Class shares prior to that date is that of the Institutional Class shares. Performance prior to June 1, 2018 has not been adjusted to reflect the lower expenses of Retirement Class shares. During this period, Retirement Class shares would have had returns similar to, but potentially higher than, Institutional Class shares due to the fact that Retirement Class shares represent interests in the same portfolio as Institutional Class shares but are subject to lower expenses.

Since Inception return based on the inception date of the Institutional Class shares.

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 will depend on a shareholder’s individual tax situation and may differ from those shown. The after-tax returns shown are not relevant to tax-exempt shareholders or shareholders who hold their Fund shares through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account. In some cases, average annual total return “After Taxes on Distributions and Sale of Fund Shares” may exceed the return “Before Taxes” and/or “After Taxes on Distributions” due to an assumed tax benefit for any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown for Institutional Class shares only. After-tax returns for each of the Retirement and Administrative Class of shares will vary.

Portfolio Management

Investment Advisor

Harbor Capital Advisors, Inc.

Subadvisor

Income Research + Management (“IR+M”) has subadvised the Fund since 2022.

Portfolio Managers

The portfolio managers are jointly and primarily responsible for the day-to-day investment decision making for the Fund.

William A. O’Malley, CFA

Income Research + Management

Mr. O’Malley is a Managing Principal, Senior Portfolio Manager, and Director of Investment Team at IR+M and has served as a portfolio manager for the Fund since February 2022.

James E. Gubitosi, CFA

Income Research + Management

Mr. Gubitosi is a Co-Chief Investment Officer at IR+M and has served as a portfolio manager for the Fund since February 2022.

Bill O’Neill, CFA

Income Research + Management

Mr. O’Neill is a Senior Portfolio Manager at IR+M and has served as a portfolio manager for the Fund since February 2022.

Jake Remley, CFA

Income Research + Management

Mr. Remley is a Senior Portfolio Manager at IR+M and has served as a portfolio manager for the Fund since February 2022.

Matt Walker, CFA

Income Research + Management

Mr. Walker is a Senior Portfolio Manager at IR+M and has served as a portfolio manager for the Fund since February 2022.

Rachel Campbell, CFA

Income Research + Management

Ms. Campbell is a Portfolio Manager and the Director of Securitized Research at IR+M and has served as a portfolio manager for the Fund since February 2022.

Fund Summary

Harbor Core Plus Fund

Buying and Selling Fund Shares

By Mail	Harbor Funds P.O. Box 804660 Chicago, IL 60680-4108
By Telephone	800-422-1050
By Visiting Our Website	harborcapital.com

Investors who wish to purchase, exchange or redeem shares held through a financial intermediary should contact the financial intermediary directly.

The minimum initial investment amounts are shown below. The minimums may be reduced or waived in some cases. There are no minimums for subsequent investments.

Type of Account	Retirement Class1	Institutional Class	Administrative Class2
Regular	$1,000,000	$1,000	$2,500
Individual Retirement Account (IRA)	$1,000,000	$1,000	$1,000
Custodial (UGMA/UTMA)	$1,000,000	$1,000	$1,000

2 Limited only to employer-sponsored retirement or benefit plans and financial intermediaries. There is no minimum investment for employer-sponsored retirement or benefit plans.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Harbor Disruptive Innovation Fund

Fund Summary

Investment Objective

The Fund seeks long-term growth of capital.

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Retirement Class	Institutional Class	Administrative Class	Investor Class
Management Fees	0.70%	0.70%	0.70%	0.70%
Distribution and Service (12b-1) Fees	None	None	0.25%	0.25%
Other Expenses	0.21%	0.29%	0.29%	0.40%
Total Annual Fund Operating Expenses	0.91%	0.99%	1.24%	1.35%
Expense Reimbursement1	(0.16)%	(0.16)%	(0.16)%	(0.16)%
Total Annual Fund Operating Expenses After Expense Reimbursement1	0.75%	0.83%	1.08%	1.19%

1 The Advisor has contractually agreed to limit the Fund’s operating expenses, excluding interest expense (if any), to 0.75%, 0.83%, 1.08%, and 1.19% for the Retirement Class, Institutional Class, Administrative Class, and Investor Class, respectively, through February 28, 2025. Only the Fund’s Board of Trustees may modify or terminate this agreement.

Expense Example

	One Year	Three Years	Five Years	Ten Years
Retirement	$77	$274	$488	$1,105
Institutional	$85	$299	$532	$1,198
Administrative	$110	$378	$666	$1,486
Investor	$121	$412	$724	$1,610

Portfolio Turnover

Principal Investment Strategy

Under normal market conditions, the Fund invests primarily in equity securities, principally common stocks, of companies selected based on their potential for growth tied to disruptive innovation. The Fund defines “disruptive innovation” as the development of new products, services, technologies and/or other advancements that could disrupt and displace existing businesses and business models over time. While the Fund invests primarily in securities of U.S. companies, the Fund may invest up to 25% of its assets in foreign securities, including those located in emerging market countries. The Fund invests in securities across the market capitalization spectrum.

The Fund employs a multi-manager approach to achieve its investment objective. The Fund’s investment adviser, Harbor Capital Advisors, Inc. (the “Advisor”) is responsible for selecting and overseeing investment subadvisors (each, a “Subadvisor”) for the Fund. Each Subadvisor is responsible for providing the Advisor with a model portfolio, which the Advisor will implement in its discretion in managing the Fund. Each Subadvisor has its own process for identifying and evaluating companies that, in the Subadvisor’s view, have the potential for growth tied to disruptive innovation. A Subadvisor may recommend selling holdings when it believes that such company’s prospects have deteriorated, future growth is unlikely, or for other reasons that a Subadvisor may identify. The Advisor is responsible for allocating the Fund’s assets among each Subadvisor’s strategy as well as implementing each strategy (which includes buying and selling securities as recommended by each Subadvisor). The Advisor does not expect to independently identify securities for investment for the Fund. The Advisor will determine allocations between each Subadvisor’s strategy and adjust those allocations over time based upon its qualitative and quantitative assessment of each strategy and how those strategies work in combination to produce what the Advisor believes is an enhanced risk-adjusted investment outcome for the Fund.

Holdings are expected to be diversified across sectors, but the Fund may, from time to time, have substantial exposure to a particular sector. Sector allocations are the result of the investment process for the Fund.

The equity securities in which the Fund invests include common stocks as well as preferred securities. The Fund may invest in securities issued by equity real estate investment trusts (REITs). The Fund may also purchase American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), and Global Depositary Receipts (GDRs), which are certificates typically issued by a bank or trust company that represent ownership interests in securities issued by a foreign or domestic company.

The Advisor has selected 4BIO Partners LLP (“4BIO Capital”), NZS Capital, LLC (“NZS Capital”), Sands Capital Management, LLC (“Sands Capital”), Tekne Capital Management, LLC (“Tekne”) and Westfield Capital Management Company, L.P. (“Westfield”) to each serve as a Subadvisor to the Fund.

4BIO Capital recommends securities to the Advisor that reflect 4BIO Capital’s focus on new companies developing emerging technologies to disrupt the advanced therapies space, which includes gene therapy, gene editing, cell therapy, ribonucleic acid (RNA) therapy (treatments that target RNA or deliver it to cells), targeted therapies (cancer treatments targeted at specific genes and proteins) and microbiome (the collection of microorganisms living in or on the human body). 4BIO Capital assesses company valuations with a view toward their future potential value creation and typically recommends divestment either upon the company’s acquisition

Fund Summary

Harbor Disruptive Innovation Fund

by another market player or when 4BIO Capital believes that future growth is unlikely.

NZS Capital recommends securities of companies to the Advisor that it believes to be highly adaptable to the disruption presented by the transition of economies from analog to digital. Though many of the companies identified by NZS Capital for investment are in the technology and communication segments of the market, NZS Capital believes that disruption is increasingly impacting all sectors of the economy and may identify companies for investment across sectors.

Sands Capital recommends securities to the Advisor based on Sands Capital’s belief that disruptive innovation improves upon the status quo, whether the innovations are on a large or small scale. Sands Capital identifies companies that it believes to have a leadership position in a promising business space, a significant competitive advantage, a clear mission, a value-add focus, financial strength and a rational valuation relative to the market and their business prospects. Sands Capital uses bottom-up research to identify companies across all sectors that it believes are benefitting from structural changes and secular trends that are distinct from cyclical economic factors.

Tekne recommends securities to the Advisor based on Tekne’s belief that a disruptive innovation company is one that creates, uses or enables technology to change or influence an existing or new workflow, product or service. Tekne seeks to identify investments that it believes will derive success from longer-term growth rather than near-term momentum. Tekne relies on its expertise in the telecommunications, media and technology sectors as well as related industries such as fin-tech.

Westfield recommends securities to the Advisor based on Westfield’s belief that disruptive innovation companies are those providing disruptive products or services to large addressable markets and that maintain a culture of continued innovation as they gain market share. Westfield will primarily focus on U.S. markets with a specialization in technology and health care.

Principal Risks

Disruptive Innovation Risk: Companies that the Subadvisor and/or Advisor, as applicable, believes have the potential for growth tied to disruptive innovation may not in fact be successful. Companies developing new technologies, creating solutions, providing disruptive products or services, or which the Subadvisor and/or Advisor, as applicable, believes to have leadership positions or competitive advantages may not be able to capitalize on those developments or positions. Such companies may encounter competition, regulation or other barriers. These companies may also be exposed to risks applicable to sectors other than the disruptive innovation theme

for which they are chosen, and the securities issued by these companies may underperform the securities of other companies. The Fund may invest in a company that does not currently derive any revenue from disruptive innovations or technologies, and there is no assurance that a company will derive any revenue from disruptive innovations in the future. A disruptive innovation may constitute a small portion of a company’s overall business. As a result, the success of a disruptive innovation may not affect the value of the equity securities issued by the company.

Equity Risk: The values of equity or equity-related securities may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. They may also decline due to factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. Equity securities generally have greater price volatility than fixed income securities.

Multi-Manager Risk: The Subadvisors’ investment styles and security recommendations may not always be complementary, which could affect the performance of the Fund. Moreover, the allocation of Fund assets among Subadvisors may lead the Fund to underperform relative to how it could have performed with a different allocation between Subadvisors.

Non-Discretionary Implementation Risk: Because the Fund is managed pursuant to model portfolios provided by non-discretionary Subadvisors that construct the model portfolios but have no authority to effect trades for the Fund’s portfolio, it is expected that the Advisor will effect trades on a periodic basis as the Advisor receives the model portfolios, and therefore less frequently than would typically be the case if the Fund employed discretionary subadvisors that effected trades for the Fund’s portfolio directly. Given that values of investments change with market conditions, a trade may ultimately be less advantageous for the Fund at the time of implementation than it would have been if it were implemented at the time the non-discretionary Subadvisor included it in its model portfolio. This could cause the Fund’s return to be lower than if the Fund employed discretionary subadvisors.

Emerging Market Risk: Foreign securities risks are more significant in emerging market countries. These countries may have relatively unstable governments and less-established market economies than developed countries. Emerging markets may face greater social, economic, regulatory and political uncertainties. These risks make emerging market securities more volatile and less liquid than securities issued in more developed countries. Securities exchanges in emerging markets may suspend listed securities from trading for substantially longer periods of time than exchanges in developed markets, including for periods of a year or longer. If the Fund is holding a suspended security, that security would become completely illiquid as the Fund would not be able to dispose of the security

Fund Summary

Harbor Disruptive Innovation Fund

until the suspension is lifted. In such instances, it can also be difficult to determine an appropriate valuation for the security because of a lack of trading and uncertainty as to when trading may resume.

Foreign Currency Risk: As a result of the Fund’s investments in securities denominated in, and/or receiving revenues in, foreign currencies, the Fund will be subject to currency risk. Currency risk is the risk that foreign currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency hedged. In either event, the dollar value of an investment in the Fund would be adversely affected.

Growth Style Risk: Over time, a growth oriented investing style may go in and out of favor, which may cause the Fund to underperform other equity funds that use different investing styles.

REIT Risk: Investing in REITs will subject the Fund to additional risks. The REITs in which the Fund invests may decline in value as a result of factors affecting the real estate sector, such as changes in real estate values, changes in property taxes and government regulation affecting zoning, land use and rents, changes in interest rates, changes in the cash flow of underlying real estate assets, levels of occupancy, and market conditions, as well as the management skill and creditworthiness of the issuer. Investments in REITs are also subject to additional risks, including the risk that REITs are unable to generate cash flow to make distributions to unitholders and fail to qualify for favorable tax treatment under the Internal Revenue Code of 1986, as amended.

exposure through less advantageous or indirect investments or forgo the investment at the time.

Small and Mid Cap Risk: The Fund’s performance may be more volatile because it may invest in issuers that are smaller companies. Smaller companies may have limited product lines, markets and financial resources. Securities of smaller companies are usually less stable in price and less liquid than those of larger, more established companies. Additionally, small and mid cap stocks may fall out of favor relative to large cap stocks, which may cause the Fund to underperform other equity funds that focus on large cap stocks.

Performance

Effective September 1, 2021, Harbor Capital began to directly manage the Fund’s portfolio using a multi-manager approach and the name and strategy of the Fund were changed. Performance prior to that date is attributable to the Fund’s prior subadvisor utilizing a different strategy.

The following bar chart and tables are intended to help you understand the risks and potential rewards of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Class has varied from one calendar year to another over the periods shown. The table shows how the Fund’s average annual total returns of the share classes presented compared to the returns of the Fund’s benchmark index and an additional index, which include securities with investment characteristics similar to those held by the Fund. Please note that the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. To obtain updated performance information please visit the Fund’s website at harborcapital.com or call 800-422-1050.

Calendar Year Total Returns for Institutional Class Shares

During the time periods shown in the bar chart, the Fund’s highest and lowest returns for a calendar quarter were:

	Total Returns	Quarter/Year
Best Quarter	41.44%	Q2 2020
Worst Quarter	-30.16%	Q2 2022

Fund Summary

Harbor Disruptive Innovation Fund

Average Annual Total Returns — As of December 31, 2023

	One Year	Annualized			Inception Date
	One Year	Five Years	Ten Years	Since Inception	Inception Date
Harbor Disruptive Innovation Fund
Retirement Class* Before Taxes	33.33%	10.32%	8.74%	5.62%	03-01-2016
Institutional Class Before Taxes	33.01%	10.22%	8.65%	5.59%	11-01-2000
After Taxes on Distributions	33.01%	5.35%	4.69%	N/A
After Taxes on Distributions and Sale of Fund Shares	19.54%	7.83%	6.28%	N/A
Administrative Class Before Taxes	32.66%	9.95%	8.38%	10.42%	11-01-2002
Investor Class Before Taxes	32.37%	9.81%	8.26%	10.29%	11-01-2002
Comparative Indices (reflects no deduction for fees, expenses or taxes)
S&P 500 Index^	26.29%	15.69%	12.03%	7.38%
Russell 3000® Growth Index^^	41.21%	18.85%	14.33%	7.33%

^^Since Inception return based on the inception date of the Institutional Class shares.

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 will depend on a shareholder’s individual tax situation and may differ from those shown. The after-tax returns shown are not relevant to tax-exempt shareholders or shareholders who hold their Fund shares through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account. In some cases, average annual total return “After Taxes on Distributions and Sale of Fund Shares” may exceed the return “Before Taxes” and/or “After Taxes on Distributions” due to an assumed tax benefit for any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown for Institutional Class shares only. After-tax returns for each of the Retirement, Administrative, and Investor Class of shares will vary.

Portfolio Management

Investment Advisor

Harbor Capital Advisors, Inc.

Portfolio Managers

The portfolio managers are jointly and primarily responsible for the day-to-day investment decision making for the Fund.

Spenser P. Lerner, CFA, Head of Multi-Asset Solutions, Managing Director and Portfolio Manager of Harbor Capital Advisors, Inc., has managed the Fund since 2021.

Kristof Gleich, CFA, President & Chief Investment Officer of Harbor Capital Advisors, Inc., has managed the Fund since 2021.

Subadvisors

The Advisor has engaged 4BIO Capital, NZS Capital, Sands Capital, Tekne and Westfield as Subadvisors since 2021 to provide investment management services to the Fund on a non-discretionary basis.

Fund Summary

Harbor Disruptive Innovation Fund

Buying and Selling Fund Shares

By Mail	Harbor Funds P.O. Box 804660 Chicago, IL 60680-4108
By Telephone	800-422-1050
By Visiting Our Website	harborcapital.com

Investors who wish to purchase, exchange or redeem shares held through a financial intermediary should contact the financial intermediary directly.

The minimum initial investment amounts are shown below. The minimums may be reduced or waived in some cases. There are no minimums for subsequent investments.

Type of Account	Retirement Class1	Institutional Class	Administrative Class2	Investor Class
Regular	$1,000,000	$50,000	$50,000	$2,500
Individual Retirement Account (IRA)	$1,000,000	$50,000	N/A	$1,000
Custodial (UGMA/UTMA)	$1,000,000	$50,000	N/A	$1,000

2 Limited only to employer-sponsored retirement or benefit plans and financial intermediaries. There is no minimum investment for employer-sponsored retirement or benefit plans.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Harbor Diversified International All Cap Fund

Fund Summary

Investment Objective

The Fund seeks long-term growth of capital.

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Retirement Class	Institutional Class	Administrative Class	Investor Class
Management Fees	0.75%	0.75%	0.75%	0.75%
Distribution and Service (12b-1) Fees	None	None	0.25%	0.25%
Other Expenses	0.07%	0.15%	0.15%	0.26%
Total Annual Fund Operating Expenses	0.82%	0.90%	1.15%	1.26%
Expense Reimbursement1	(0.10)%	(0.10)%	(0.10)%	(0.10)%
Total Annual Fund Operating Expenses After Expense Reimbursement1	0.72%	0.80%	1.05%	1.16%

1 The Advisor has contractually agreed to limit the Fund’s operating expenses, excluding interest expense (if any), to 0.72% 0.80%, 1.05%, and 1.16% for the Retirement Class, Institutional Class, Administrative Class, and Investor Class, respectively, through February 28, 2025. Only the Fund’s Board of Trustees may modify or terminate this agreement.

Expense Example

	One Year	Three Years	Five Years	Ten Years
Retirement	$74	$252	$445	$1,004
Institutional	$82	$277	$489	$1,099
Administrative	$107	$355	$623	$1,389
Investor	$118	$390	$682	$1,514

Portfolio Turnover

Principal Investment Strategy

The Fund invests primarily (no less than 65% of its total assets under normal market conditions) in common and preferred stocks of foreign companies, including those located in emerging market countries.

The Subadvisor’s investment strategy focuses on identifying attractive long-term investment opportunities that can arise as a result of certain capital cycle, or supply-side, conditions. Capital cycle investing is based on the concept that the prospect of high returns will attract excessive capital and competition and the prospect of low returns will excessively depress new capital investments and discourage competition. The assessments of how management responds to the forces of the capital cycle through its capital allocation strategy and how it is incentivized are both critical to the investment outcome. While capital cycles are often observed at an industry level, particularly where the investment merits of an individual business are influenced by the rationality of actors within a given competitive ecosystem, they are first identified through bottom-up analysis at the company level. The Subadvisor broadly characterizes investments within two opposite points of the capital cycle:

■

High Return Phase: Investments in the top half of the capital cycle, where high rates of return within a business and/or industry are being attained, are often characterized as having intrinsic pricing power that allow them to fend off competition and excess capital that would otherwise be drawn to the prospects of high returns. These types of investments can also be characterized as having a consolidated industry market structure with high barriers to entry.

■

Depressed Return Phase: Investments in the bottom half of the capital cycle, where rates of return have fallen to or below the cost of capital and where capital is being repelled as a result, are often characterized as contrarian, deep value investments where an improvement in the economic returns of a business are not accurately discounted by the broad market. A consolidating market structure, where supply and competition are removed, or a radical shift in management strategy, are often conditions leading to these types of investments.

The Subadvisor uses fundamental, bottom-up qualitative analysis to evaluate businesses and the industry within which they operate. Research meetings with company management represent a significant aspect of the analysis conducted by the Subadvisor. Companies that the Subadvisor finds attractive include those that:

■

Deploy capital effectively and efficiently

■

Have high insider ownership and/or where company management are appropriately incentivized to focus on long-term results

■

Operate in a monopolistic, oligopolistic or consolidating industry

■

Show improving or high and sustainable returns on invested capital

■

Generate attractive or improving free cash-flow

Given the contrarian and long-term nature of the capital cycle, the Subadvisor’s investment strategy tends to result in a portfolio of investments that can differ significantly from the Fund’s benchmark index, with average holding periods of seven years or more for individual company investments. As part of its investment process, the Subadvisor considers environmental, social and governance (“ESG”) factors that it believes may have a material

Fund Summary

Harbor Diversified International All Cap Fund

impact on an issuer and the value of its securities. As a result, the key ESG considerations may vary depending on the industry, sector, geographic region or other factors and the core business of each issuer.

The Subadvisor allocates responsibility for sourcing investment opportunities among its portfolio managers by regions of the world, with different portfolio managers responsible for each of Europe, Japan, the Pacific Basin, emerging markets, and North America. The Subadvisor maintains an aggregate portfolio that is broadly regionally neutral relative to the benchmark index. All of the portfolio managers employ the capital cycle approach to investing across their respective regions in order to identify individual companies for investment. The investment ideas generated across each of the four regions are then combined into the Fund’s overall portfolio. This results in a portfolio that generally maintains investments in between 250 and 350 companies. While inherently diversified, a bias towards smaller and mid cap businesses in niche industries, coupled with a particularly long holding period, result in a portfolio that is significantly differentiated from the Fund’s benchmark index. The Fund may invest in securities denominated in, and/or receiving revenues in, foreign currencies.

Principal Risks

Capital Cycle Risk: The Subadvisor’s assessment of the capital cycle for a particular industry or company may be incorrect. Investing in companies at inopportune phases of the capital cycle can result in the Fund purchasing company stock at pricing levels that are higher than the market dynamics would support and therefore subject the Fund to greater risk that the stock price would decline rather than increase over time.

Foreign Securities Risk: An investment in the Fund is subject to special risks in addition to those of U.S. securities. These risks include heightened political and economic risks, greater volatility, currency fluctuations, higher transaction costs, delayed settlement, possible foreign controls on investment, possible sanctions by governmental bodies of other countries and less stringent investor protection and disclosure standards of foreign markets. Foreign securities are sometimes less liquid and harder to value than securities of U.S. issuers. The securities markets of many foreign countries are relatively small, with a limited number of companies representing a small number of industries. If foreign securities are denominated and traded in a foreign currency, the value of the Fund’s foreign holdings can be affected by currency exchange rates and exchange control regulations. The Fund’s investments in foreign securities may also be subject to foreign withholding taxes.

Global economies and financial markets are becoming increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market.

affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. Equity securities generally have greater price volatility than fixed income securities.

Geographic Focus Risk: The Fund may invest a substantial amount of its assets in securities of issuers located in a single country or geographic region. As a result, any changes to the regulatory, political, social or economic conditions in such country or geographic region will generally have greater impact on the Fund than such changes would have on a more geographically diversified fund and may result in increased volatility and greater losses.

Fund Summary

Harbor Diversified International All Cap Fund

Performance

The following bar chart and tables are intended to help you understand the risks and potential rewards of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Class has varied from one calendar year to another over the periods shown. The table shows how the Fund’s average annual total returns of the share classes presented compared to the returns of the Fund’s benchmark index, which includes securities with investment characteristics similar to those held by the Fund. Please note that the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. To obtain updated performance information please visit the Fund’s website at harborcapital.com or call 800-422-1050.

Calendar Year Total Returns for Institutional Class Shares

During the time periods shown in the bar chart, the Fund’s highest and lowest returns for a calendar quarter were:

	Total Returns	Quarter/Year
Best Quarter	19.80%	Q4 2020
Worst Quarter	-27.37%	Q1 2020

Average Annual Total Returns — As of December 31, 2023

	One Year	Annualized			Inception Date
	One Year	Five Years	Ten Years	Since Inception	Inception Date
Harbor Diversified International All Cap Fund
Retirement Class* Before Taxes	14.72%	7.81%	N/A	5.34%	03-01-2016
Institutional Class Before Taxes	14.61%	7.72%	N/A	5.27%	11-02-2015
After Taxes on Distributions	14.07%	7.15%	N/A	4.69%
After Taxes on Distributions and Sale of Fund Shares	9.24%	6.20%	N/A	4.22%
Administrative Class Before Taxes	14.31%	7.46%	N/A	5.01%	11-02-2015
Investor Class Before Taxes	14.16%	7.31%	N/A	4.88%	11-02-2015
Comparative Index (reflects no deduction for fees, expenses or taxes)
MSCI All Country World Ex. U.S. (ND)^	15.62%	7.08%	N/A	5.45%

Since Inception return based on the inception date of the Institutional Class shares.

Portfolio Management

Investment Advisor

Harbor Capital Advisors, Inc.

Subadvisor

Marathon Asset Management Limited (“Marathon-London”) has subadvised the Fund since 2015.