The Fund seeks total return that corresponds with the total return of a broad U.S. investment-grade bond market index.

The following tables describe the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund or other Nuveen mutual funds. More information about these and other discounts, as well as eligibility requirements for each share class, is available from your financial advisor and in “How You Can Buy and Sell Shares” on page 192 of the Fund’s Prospectus and “Purchase and Redemption of Fund Shares” on page 105 of the Fund’s Statement of Additional Information. In addition, more information about sales charge discounts and waivers for purchases of shares through specific financial intermediaries is set forth in the appendix to the Fund’s Prospectus entitled “Variations in Sales Charge Reductions and Waivers Available Through Certain Intermediaries.

The tables and examples below do not reflect any commissions that shareholders may be required to pay directly to their financial intermediaries when buying or selling Class I shares.

SHAREHOLDER FEES (fees paid directly from your investment)

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

This example is intended to help you compare the cost of investing in shares of 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 and then redeem all your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses, before fee waivers and/or expense reimbursements, remain the same. The example assumes that the Fund’s fee waiver and/or expense reimbursement arrangements will each remain in place for the durations noted in the table above. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

The Fund pays transaction costs when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the fiscal year ended March 31, 2024, the Fund’s portfolio turnover rate was 14% of the average value of its portfolio.

Under normal circumstances, the Fund invests at least 80% of its assets in bonds within its benchmark and portfolio tracking index, the Bloomberg U.S. Aggregate Bond Index (the “Index”). The Fund uses a sampling technique to create a portfolio that closely matches the overall investment characteristics of the Index (for example, duration, sector diversification and credit quality) without investing in all of the securities in its index. At times the Fund may purchase securities not held in the Index, but which Teachers Advisors, LLC (“Advisors”) believes have similar investment characteristics to securities held in its index. Generally, the Fund intends to invest in a wide spectrum of public, investment-grade, taxable debt securities denominated in U.S. dollars including government securities, as well as mortgage-backed, commercial mortgage-backed and asset-backed securities. The Fund’s investments in mortgage-backed securities may include pass-through securities sold by private, governmental and government-related organizations and U.S. Government-sponsored enterprises (“GSEs”), to the extent that such instruments are held by the Index. The Fund may also invest in securities having a variable or floating interest rate. The Fund generally will invest in foreign securities denominated in U.S. dollars only to the extent they are included or eligible to be included in the Index. For purposes of the 80% investment policy, the term “assets” means net assets, plus the amount of any borrowings for investment purposes.

The securities purchased by the Fund will mainly be high-quality instruments rated in the top four credit categories by a nationally recognized statistical rating organization (“NRSRO”) or deemed to be of the same quality by Advisors using its own credit quality analysis. The Fund may continue to hold instruments that were rated as high-quality when purchased, but which subsequently are downgraded to below-investment-grade status or have their ratings withdrawn by one or more rating agencies.

Because the return of the Index is not reduced by investment and other operating expenses, the Fund’s ability to match the Index is negatively affected by the costs of buying and selling securities, as well as other fees and expenses. The use of the Index by the Fund is not a fundamental policy of the Fund and may be changed without shareholder approval.

The Fund is classified as a diversified investment company, as defined under the Investment Company Act of 1940, as amended (the “1940 Act”). However,

the Fund may become non-diversified under the 1940 Act without the approval of Fund shareholders solely as a result of a change in relative market capitalization or index weighting of one or more constituents of its benchmark index, the Bloomberg U.S. Aggregate Bond Index, which the Fund seeks to track.

· Interest Rate Risk (a type of Market Risk)—The risk that changes in interest rates can adversely affect the value or liquidity of, and income generated by, fixed-income investments. This risk is heightened to the extent the Fund invests in longer duration fixed-income investments and during periods when prevailing interest rates are changing. There is a risk that interest rates across the financial system may change, possibly significantly and/or rapidly. In general, changing interest rates, including rates that fall below zero, or a lack of market participants may lead to decreased liquidity and increased volatility in the fixed-income or debt markets, making it more difficult for the Fund to sell fixed-income investments. When interest rates change, the values of longer duration fixed-income securities usually change more than the values of shorter duration fixed-income securities. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. Other factors that may affect the value of debt securities include, but are not limited to, economic, political, public health, and other crises and responses by governments and companies to such crises.

· Prepayment Risk—The risk that, during periods of falling interest rates, borrowers may pay off their mortgage loans sooner than expected, forcing the Fund to reinvest the unanticipated proceeds at lower interest rates and resulting in a decline in income.

· Extension Risk—The risk that, during periods of rising interest rates, borrowers may pay off their mortgage loans later than expected, preventing the Fund from reinvesting principal proceeds at higher interest rates and resulting in less income than potentially available.

· Issuer Risk (often called Financial Risk)—The risk that an issuer’s earnings prospects, credit rating and overall financial position will deteriorate, causing a decline in the value of the issuer’s financial instruments over short or extended periods of time.

· Credit Risk (a type of Issuer Risk)—The risk that the issuer of fixed-income investments may not be able or willing, or may be perceived (whether by market participants, rating agencies, pricing services or otherwise) as not able or willing, to meet interest or principal payments when the payments become due.

· Credit Spread Risk—The risk that credit spreads (i.e., the difference in yield between securities that is due to differences in each security’s respective credit quality) may increase when market participants believe that bonds generally have a greater risk of default, which could result in a decline in the market values of the Fund’s debt securities.

· Income Volatility Risk—The risk that the level of current income from a portfolio of fixed-income investments may decline in certain interest rate environments.

· Market Volatility, Liquidity and Valuation Risk (types of Market Risk)—The risk that volatile or dramatic reductions in trading activity make it difficult for the Fund to properly value its investments and that the Fund may not be able to purchase or sell an investment at an attractive price, if at all.

· Index Risk—The risk that the Fund’s performance may not correspond to its benchmark index for any period of time and may underperform such index or the overall financial market. Additionally, to the extent that the Fund’s investments vary from the composition of its benchmark index, the Fund’s performance could potentially vary from the index’s performance to a greater extent than if the Fund merely attempted to replicate the index.

· Fixed-Income Foreign Investment Risk—Investment in fixed-income securities or financial instruments of foreign issuers involves increased risks due to adverse issuer, political, regulatory, currency, market or economic developments as well as armed conflicts. These developments may impact the ability of a foreign debt issuer to make timely and ultimate payments on its debt obligations to the Fund or impair the Fund’s ability to enforce its rights against the foreign debt issuer. These risks are heightened in emerging or developing markets. Foreign investments may also have lower overall liquidity and be more difficult to value than investments in U.S. issuers. Foreign investments may also be subject to risk of loss because of more or less foreign government regulation, less public information, less stringent investor protections, and less stringent accounting, corporate governance, financial reporting and disclosure standards. Changes in the value of foreign currencies may make the return on an investment increase or decrease, unrelated to the quality or performance of the investment itself. The imposition of sanctions, exchange controls (including repatriation restrictions), confiscations, trade restrictions (including tariffs) and other restrictions by the United States or other governments may also negatively impact the Fund’s investments. Economic sanctions and other similar governmental actions or developments could, among other things, effectively restrict or eliminate the Fund’s ability to purchase or sell certain foreign securities or groups of foreign securities, and/or thus may make the Fund’s investments in such securities less liquid (or illiquid) or more difficult to value. The type and severity of sanctions and other measures that may be imposed could vary broadly in scope, and their impact is impossible to predict.

· U.S. Government Securities Risk—Securities issued by the U.S. Government or one of its agencies or instrumentalities may receive varying levels of support from the U.S. Government, which could affect the Fund’s ability to recover should they default. To the extent the Fund invests significantly in securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the securities of the U.S. Government or its agencies or instrumentalities in which the Fund invests may have a significant impact on the Fund’s performance.

· Illiquid Investments Risk—The risk that illiquid investments may be difficult to sell for the value at which they are carried, if at all, or at any price within the desired time frame.

· Downgrade Risk—The risk that securities are subsequently downgraded should Advisors and/or rating agencies believe the issuer’s business outlook or creditworthiness has deteriorated.

· Call Risk—The risk that, during periods of falling interest rates, an issuer may call (or repay) a fixed-income security prior to maturity, resulting in a decline in the Fund’s income.

· Floating and Variable Rate Securities Risk—Floating and variable rate securities provide for a periodic adjustment in the interest rate paid on the securities. The rate adjustment intervals may be regular and range from daily up to annually, or may be based on an event, such as a change in the prime rate. Floating and variable rate securities may be subject to greater liquidity risk than other debt securities, meaning that there may be limitations on the Fund’s ability to sell the securities at any given time. Such securities also may lose value.

· Non-Diversification Risk—While the Fund is considered to be a diversified investment company under the 1940 Act, the Fund may become non-diversified under the 1940 Act without Fund shareholder approval when necessary to continue to track its benchmark index. Non-diversified status means that the Fund can invest a greater percentage of its assets in the securities of a single issuer than a diversified fund. Investing in a non-diversified fund involves greater risk than investing in a diversified fund because a loss in value of a particular investment may have a greater effect on the fund’s return since that investment may represent a larger portion of the fund’s total portfolio assets.

The following chart and table help illustrate some of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year. The bar chart shows the annual total returns of Class R6 of the Fund, before taxes, in

each full calendar year for the last ten years. Because the expenses vary across share classes, the performance of Class R6 may vary from the other share classes. Below the bar chart are the best and worst returns of Class R6 for a calendar quarter during the full calendar-year periods covered by the bar chart. The performance table following the bar chart shows the Fund’s average annual total returns for Class A, Class I, Premier Class, Class R6, Retirement Class and Class W over the applicable one-year, five-year, ten-year and since-inception periods ended December 31, 2023, and how those returns compare to those of the Fund’s benchmark index. In accordance with new regulatory requirements, the Fund has selected the Bloomberg U.S. Aggregate Bond Index, which represents a broad measure of market performance, and is generally representative of the market sectors or types of investments in which the Fund invests. After-tax performance is shown only for Class R6 shares, and after-tax returns for the other classes of shares will vary from the after-tax returns presented for Class R6 shares.

The returns shown below reflect previous agreements by Advisors to waive or reimburse the Fund for certain fees and expenses. Without these waivers and reimbursements, the returns of the Fund would have been lower. Past performance of the Fund (before and after taxes) is not necessarily an indication of how it will perform in the future. The benchmark index listed below is unmanaged, and you cannot invest directly in an index. The returns for the benchmark index reflect no deduction for fees, expenses or taxes.

For current performance information of each share class, including performance to the most recent month-end, please visit www.nuveen.com/performance or call 800-257-8787.

ANNUAL TOTAL RETURNS FOR CLASS R6 SHARES (%)^†

Nuveen Bond Index Fund

^† The year-to-date return as of the most recent calendar quarter, which ended on June 30, 2024, was -0.53%.

Best quarter: 6.64%, for the quarter ended December 31, 2023. Worst quarter: -5.89%, for the quarter ended March 31, 2022.

The Fund seeks total return, primarily through current income.

The following tables describe the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund or other Nuveen mutual funds. More information about these and other discounts, as well as eligibility requirements for each share class, is available from your financial advisor and in “How You Can Buy and Sell Shares” on page 192 of the Fund’s Prospectus and “Purchase and Redemption of Fund Shares” on page 105 of the Fund’s Statement of Additional Information. In addition, more information about sales charge discounts and waivers for purchases of shares through specific financial intermediaries is set forth in the appendix to the Fund’s Prospectus entitled “Variations in Sales Charge Reductions and Waivers Available Through Certain Intermediaries.

The tables and examples below do not reflect any commissions that shareholders may be required to pay directly to their financial intermediaries when buying or selling Class I shares.

SHAREHOLDER FEES (fees paid directly from your investment)

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

This example is intended to help you compare the cost of investing in shares of 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 and then redeem all your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses, before fee waivers and/or expense reimbursements, remain the same. The example assumes that the Fund’s fee waiver and/or expense reimbursement arrangements will each remain in place for the durations noted in the table above. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

The Fund pays transaction costs when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the fiscal year ended March 31, 2024, the Fund’s portfolio turnover rate was 62% of the average value of its portfolio.

Under normal circumstances, the Fund invests at least 80% of its assets in bonds. For these purposes, bonds include fixed-income securities of all types. The Fund primarily invests in a broad range of investment-grade bonds and fixed-income securities, including, but not limited to, U.S. Government securities, corporate bonds, mortgage-backed and other asset-backed securities, convertible and preferred securities, senior loans and loan participations and assignments and notes. The Fund may also invest in other fixed-income securities, including those of non-investment-grade quality (usually called “high-yield” or “junk bonds”). Securities of non-investment-grade quality are speculative in nature. The Fund does not rely exclusively on rating agencies when making investment decisions. Instead, the Fund’s investment adviser, Teachers Advisors, LLC (“Advisors”), performs its own credit analysis, paying particular attention to economic trends and other market events. The Fund may also invest in securities having a variable or floating interest rate. Individual securities or sectors may be overweighted or underweighted relative to the Fund’s benchmark index, the Bloomberg U.S. Aggregate Bond Index, when Advisors believes that such overweight or underweight may cause the Fund to outperform the index. For purposes of the 80% investment policy, the term “assets” means net assets, plus the amount of any borrowings for investment purposes.

The Fund may invest in fixed-income securities of any duration. As of May 31, 2024, the duration of the Fund’s benchmark index, the Bloomberg U.S. Aggregate Bond Index, was 6.09 years.

The Fund’s investments in mortgage-backed securities can include pass-through securities sold by private, governmental and government-related organizations and collateralized mortgage obligations (“CMOs”). Mortgage pass-through securities are created when mortgages are pooled together and interests in the pool are sold to investors. The cash flow from the underlying mortgages is “passed through” to investors in periodic principal and interest payments. CMOs are obligations that are fully collateralized directly or indirectly by a pool of mortgages from which payments of principal and interest are dedicated to the payment of principal and interest on the CMO.

The Fund may use an investment strategy called “mortgage rolls” (also referred to as “dollar rolls”), in which the Fund sells securities for delivery in the current month and simultaneously contracts with a counterparty to repurchase

similar (same type, coupon and maturity) but not identical securities on a specified future date. The Fund loses the right to receive principal and interest paid on the securities sold. However, the Fund would benefit to the extent of any price received for the securities sold and the lower forward price for the future purchase (often referred to as the “drop”) plus the interest earned on the short-term investment awaiting the settlement date of the forward purchase. If such benefits exceed the income and gain or loss due to mortgage repayments that would have been realized on the securities sold as part of the mortgage roll, the use of this technique will enhance the investment performance of the Fund compared with what such performance would have been without the use of mortgage rolls. Realizing benefits from the use of mortgage rolls depends upon the ability of Advisors to correctly predict mortgage prepayments and interest rates.

The Fund may also engage in relative value trading, a strategy in which the Fund reallocates assets across different sectors and maturities. Relative value trading is designed to enhance the Fund’s returns but increases the Fund’s portfolio turnover rate.

The Fund may purchase and sell futures, options, swaps, forwards and other fixed-income derivative instruments to carry out the Fund’s investment strategies. The Fund may also invest in foreign securities, including emerging markets fixed-income securities and non-dollar-denominated instruments. Under most circumstances, the Fund’s investments in fixed-income securities of foreign issuers constitute less than 25% of the Fund’s assets.

· Interest Rate Risk (a type of Market Risk)—The risk that changes in interest rates can adversely affect the value or liquidity of, and income generated by, fixed-income investments. This risk is heightened to the extent the Fund invests in longer duration fixed-income investments and during periods when prevailing interest rates are changing. There is a risk that interest rates across the financial system may change, possibly significantly and/or rapidly. In general, changing interest rates, including rates that fall below zero, or a lack of market participants may lead to decreased liquidity and increased volatility in the fixed-income or debt markets, making it more difficult for the Fund to sell fixed-income investments. When interest rates change, the values of longer duration fixed-income securities usually change more than the values of shorter duration fixed-income securities. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. Other factors that may affect the value of debt securities include, but are not limited to, economic, political, public

health, and other crises and responses by governments and companies to such crises.

· Prepayment Risk—The risk that, during periods of falling interest rates, borrowers may pay off their mortgage loans sooner than expected, forcing the Fund to reinvest the unanticipated proceeds at lower interest rates and resulting in a decline in income.

· Extension Risk—The risk that, during periods of rising interest rates, borrowers may pay off their mortgage loans later than expected, preventing the Fund from reinvesting principal proceeds at higher interest rates and resulting in less income than potentially available.

· Issuer Risk (often called Financial Risk)—The risk that an issuer’s earnings prospects, credit rating and overall financial position will deteriorate, causing a decline in the value of the issuer’s financial instruments over short or extended periods of time.

· Credit Risk (a type of Issuer Risk)—The risk that the issuer of fixed-income investments may not be able or willing, or may be perceived (whether by market participants, rating agencies, pricing services or otherwise) as not able or willing, to meet interest or principal payments when the payments become due.

· Credit Spread Risk—The risk that credit spreads (i.e., the difference in yield between securities that is due to differences in each security’s respective credit quality) may increase when market participants believe that bonds generally have a greater risk of default, which could result in a decline in the market values of the Fund’s debt securities.

· Income Volatility Risk—The risk that the level of current income from a portfolio of fixed-income investments may decline in certain interest rate environments.

· Market Volatility, Liquidity and Valuation Risk (types of Market Risk)—The risk that volatile or dramatic reductions in trading activity make it difficult for the Fund to properly value its investments and that the Fund may not be able to purchase or sell an investment at an attractive price, if at all.

· Fixed-Income Foreign Investment Risk—Investment in fixed-income securities or financial instruments of foreign issuers involves increased risks due to adverse issuer, political, regulatory, currency, market or economic developments as well as armed conflicts. These developments may impact the ability of a foreign debt issuer to make timely and ultimate payments on its debt obligations to the Fund or impair the Fund’s ability to enforce its rights against the foreign debt issuer. These risks are heightened in emerging or developing markets. Foreign investments may also have lower overall liquidity and be more difficult to value than investments in U.S. issuers. Foreign investments may also be subject to risk of loss because of more or less foreign government regulation, less public information, less stringent investor protections, and less stringent accounting, corporate

governance, financial reporting and disclosure standards. Changes in the value of foreign currencies may make the return on an investment increase or decrease, unrelated to the quality or performance of the investment itself. The imposition of sanctions, exchange controls (including repatriation restrictions), confiscations, trade restrictions (including tariffs) and other restrictions by the United States or other governments may also negatively impact the Fund’s investments. Economic sanctions and other similar governmental actions or developments could, among other things, effectively restrict or eliminate the Fund’s ability to purchase or sell certain foreign securities or groups of foreign securities, and/or thus may make the Fund’s investments in such securities less liquid (or illiquid) or more difficult to value. The type and severity of sanctions and other measures that may be imposed could vary broadly in scope, and their impact is impossible to predict.

· Active Management Risk—The risk that Advisors’ strategy, investment selection or trading execution may cause the Fund to underperform relative to the benchmark index or mutual funds with similar investment objectives and may not produce expected returns.

· Call Risk—The risk that, during periods of falling interest rates, an issuer may call (or repay) a fixed-income security prior to maturity, resulting in a decline in the Fund’s income.

· Mortgage Roll Risk—The risk that Advisors will not correctly predict mortgage prepayments and interest rates, which will diminish the Fund’s performance.

· Downgrade Risk—The risk that securities are subsequently downgraded should Advisors and/or rating agencies believe the issuer’s business outlook or creditworthiness has deteriorated.

· Non-Investment-Grade Securities Risk—Issuers of non-investment-grade securities, which are usually called “high-yield” or “junk bonds,” are typically speculative in nature, in weaker financial health and such securities can be harder to value and sell and their prices can be more volatile than more highly rated securities. While these securities generally have higher rates of interest, they also involve greater risk of default than do securities of a higher-quality rating. In times of unusual or adverse market, economic or political conditions, these securities may experience higher than normal default rates.

· Illiquid Investments Risk—The risk that illiquid investments may be difficult to sell for the value at which they are carried, if at all, or at any price within the desired time frame.

· Senior Loan Risk—Many senior loans present credit risk comparable to high-yield securities. The liquidation of the collateral backing a senior loan may not satisfy the borrower’s obligation to the Fund in the event of non-payment of scheduled interest or principal. Senior loans also expose the Fund to call risk and illiquid investments risk. The secondary market for senior loans can

be limited. Trades can be infrequent and the values for senior loans may experience volatility. In some cases, negotiations for the sale or settlement of senior loans may require weeks to complete, which may impair the Fund’s ability to raise cash to satisfy redemptions, pay dividends, pay expenses or to take advantage of other investment opportunities in a timely manner. If an issuer of a senior loan prepays or redeems the loan prior to maturity, the Fund will have to reinvest the proceeds in other senior loans or instruments that may pay lower interest rates.

· Emerging Markets Risk—The risk of foreign investment often increases in countries with emerging markets or otherwise economically tied to emerging market countries. For example, these countries may have more unstable governments than developed countries, and their economies may be based on only a few industries. Emerging market countries may also have less stringent regulation of accounting, auditing, financial reporting and recordkeeping requirements, which would affect the Fund’s ability to evaluate potential portfolio companies. As a result, there could be less information available about issuers in emerging market countries, which could negatively affect Advisors’ ability to evaluate local companies or their potential impact on the Fund’s performance. Because their financial markets may be very small, share prices of financial instruments in emerging market countries may be volatile and difficult to determine. Financial instruments of issuers in these countries may have lower overall liquidity than those of issuers in more developed countries. In addition, foreign investors such as the Fund are subject to a variety of special restrictions in many emerging market countries. Moreover, legal remedies for investors in emerging markets may be more limited, and U.S. authorities may have less ability to bring actions against bad actors in emerging market countries. The risks outlined above are often more pronounced in “frontier markets” in which the Fund may invest. Frontier markets are those emerging markets that are considered to be among the smallest, least mature and least liquid. These factors may make investing in frontier market countries significantly riskier than investing in other countries.

· U.S. Government Securities Risk—Securities issued by the U.S. Government or one of its agencies or instrumentalities may receive varying levels of support from the U.S. Government, which could affect the Fund’s ability to recover should they default. To the extent the Fund invests significantly in securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the securities of the U.S. Government or its agencies or instrumentalities in which the Fund invests may have a significant impact on the Fund’s performance.

· Floating and Variable Rate Securities Risk—Floating and variable rate securities provide for a periodic adjustment in the interest rate paid on the securities. The rate adjustment intervals may be regular and range from daily

up to annually, or may be based on an event, such as a change in the prime rate. Floating and variable rate securities may be subject to greater liquidity risk than other debt securities, meaning that there may be limitations on the Fund’s ability to sell the securities at any given time. Such securities also may lose value.

· Portfolio Turnover Risk—Depending on market and other conditions, the Fund may experience high portfolio turnover, which may result in greater transactional expenses, such as brokerage commissions, bid-ask spreads, or dealer mark-ups, and capital gains (which could increase taxes and, consequently, reduce returns).

· Derivatives Risk—The risks associated with investing in derivatives, including futures, options, swaps, forwards, and other fixed-income derivative instruments, and other similar instruments (referred to collectively as “derivatives”) may be different and greater than the risks associated with directly investing in the underlying securities and other instruments, and include leverage risk, market risk, counterparty risk, liquidity risk, operational risk and legal risk. The Fund may use more complex derivatives that might be particularly susceptible to liquidity, credit and counterparty risk. When investing in derivatives, the Fund may lose more than the principal amount invested.

The following chart and table help illustrate some of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year. The bar chart shows the annual total returns of Class R6 of the Fund, before taxes, in each full calendar year for the last ten years. Because the expenses vary across share classes, the performance of Class R6 may vary from the other share classes. Below the bar chart are the best and worst returns of Class R6 for a calendar quarter during the full calendar-year periods covered by the bar chart. The performance table following the bar chart shows the Fund’s average annual total returns for Class A, Class I, Premier Class, Class R6, Retirement Class and Class W over the applicable one-year, five-year, ten-year and since-inception periods ended December 31, 2023, and how those returns compare to those of the Fund’s benchmark index. In accordance with new regulatory requirements, the Fund has selected the Bloomberg U.S. Aggregate Bond Index, which represents a broad measure of market performance, and is generally representative of the market sectors or types of investments in which the Fund invests. After-tax performance is shown only for Class R6 shares, and after-tax returns for the other classes of shares will vary from the after-tax returns presented for Class R6 shares.

The returns shown below reflect previous agreements by Advisors to waive or reimburse the Fund for certain fees and expenses. Without these waivers and

reimbursements, the returns of the Fund would have been lower. Past performance of the Fund (before and after taxes) is not necessarily an indication of how it will perform in the future. The benchmark index listed below is unmanaged, and you cannot invest directly in an index. The returns for the benchmark index reflect no deduction for fees, expenses or taxes.

For current performance information of each share class, including performance to the most recent month-end, please visit www.nuveen.com/performance or call 800-257-8787.

ANNUAL TOTAL RETURNS FOR CLASS R6 SHARES (%)^†

Nuveen Core Bond Fund

^† The year-to-date return as of the most recent calendar quarter, which ended on June 30, 2024, was 0.37%.

Best quarter: 6.74%, for the quarter ended December 31, 2023. Worst quarter: -5.89%, for the quarter ended March 31, 2022.

The Fund seeks total return, primarily through current income, while giving special consideration to certain environmental, social and governance (“ESG”) criteria.

The following tables describe the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund or other Nuveen mutual funds. More information about these and other discounts, as well as eligibility requirements for each share class, is available from your financial advisor and in “How You Can Buy and Sell Shares” on page 192 of the Fund’s Prospectus and “Purchase and Redemption of Fund Shares” on page 105 of the Fund’s Statement of Additional Information. In addition, more information about sales charge discounts and waivers for purchases of shares through specific financial intermediaries is set forth in the appendix to the Fund’s Prospectus entitled “Variations in Sales Charge Reductions and Waivers Available Through Certain Intermediaries.

The tables and examples below do not reflect any commissions that shareholders may be required to pay directly to their financial intermediaries when buying or selling Class I shares.

SHAREHOLDER FEES (fees paid directly from your investment)

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

This example is intended to help you compare the cost of investing in shares of 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 and then redeem all your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses, before fee waivers and/or expense reimbursements, remain the same. The example assumes that the Fund’s fee waiver and/or expense reimbursement arrangements will each remain in place for the durations noted in the table above. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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

ended March 31, 2024, the Fund’s portfolio turnover rate was 142% of the average value of its portfolio.

Under normal circumstances, the Fund invests at least 80% of its assets in bonds. For these purposes, bonds include fixed-income securities of all types. The Fund primarily invests in a broad range of investment-grade bonds and fixed-income securities, including, but not limited to, U.S. Government securities, corporate bonds, taxable municipal securities and mortgage-backed or other asset-backed securities. The Fund may also invest in other fixed-income securities, including those of non-investment-grade quality (usually called “high-yield” or “junk bonds”). Securities of non-investment-grade quality are speculative in nature. The Fund may also invest in securities having a variable or floating interest rate. The Fund may invest in fixed-income securities of any duration. As of May 31, 2024, the duration of the Fund’s benchmark index, the Bloomberg U.S. Aggregate Bond Index, was 6.09 years. For purposes of the 80% investment policy, the term “assets” means net assets, plus the amount of any borrowings for investment purposes.

The Fund is actively managed and does not rely exclusively on rating agencies when making investment decisions. Instead, the Fund’s investment adviser, Teachers Advisors, LLC (“Advisors”) performs its own credit analysis, paying particular attention to economic trends and other market events. Subject to the ESG criteria and Teachers Insurance and Annuity Association of America (“TIAA”)’s proprietary Impact framework described below, individual securities or sectors may be overweighted or underweighted relative to the Fund’s benchmark index, when Advisors believes that the Fund can boost returns above that of the index.

When selecting investments for the Fund, Advisors considers certain ESG criteria or Impact framework. The Fund’s Impact framework, described in more detail below, provides direct exposure to issuers or projects that Advisors believes have the potential to have social or environmental benefits. The ESG criteria are generally implemented based on data provided by independent research vendor(s). In those limited cases where independent ESG criteria are not available for certain types of securities or for certain issuers, these securities may nonetheless be eligible for the Fund should they meet certain internal ESG criteria.

The corporate issuer evaluation process favors companies with leadership in ESG performance relative to their peers. Typically, environmental assessment categories include climate change, natural resource use, waste management and environmental opportunities. Social evaluation categories include human capital, product safety and social opportunities. Governance assessment categories include corporate governance, business ethics and government & public policy. How well companies adhere to international norms and principles and involvement in major ESG controversies (examples of which may relate to the environment, customers, human rights & community, labor rights & supply chain, and governance) are other considerations.

The ESG evaluation process with respect to corporate issuers is conducted on an industry-specific basis and involves the identification of key performance

indicators, which are given more or less relative weight compared to the broader range of potential assessment categories. When ESG concerns exist, the evaluation process gives careful consideration to how companies address the risks and opportunities they face in the context of their sector or industry and relative to their peers. The Fund will not generally invest in companies significantly involved in certain business activities including, but not limited to, the production of alcohol, tobacco, military weapons, firearms, nuclear power, thermal coal, and gambling products and services.

The ESG evaluation process with respect to government issuers favors issuers with leadership in ESG performance relative to all peers. Typically, environmental assessment categories include the issuer’s ability to protect, harness, and supplement its natural resources, and to manage environmental vulnerabilities and externalities. Social assessment categories include the issuer’s ability to develop a healthy, productive, and stable workforce and knowledge capital, and to create a supportive economic environment. Governance assessment categories include the issuer’s institutional capacity to support long-term stability and well-functioning financial, judicial, and political systems, and capacity to address environmental and social risks. The government ESG evaluation process is conducted on a global basis and reflects how an issuer’s exposure to and management of ESG risk factors may affect the long-term sustainability of its economy.

While Advisors may invest in issuers that meet these criteria, it is not required to invest in every issuer that meets these criteria. In addition, concerns with respect to one ESG assessment category may not automatically eliminate an issuer from being considered an eligible Fund investment. The ESG criteria and the Impact framework the Fund takes into consideration are both non-fundamental investment policies and may be changed without the approval of the Fund’s shareholders.

The Fund is not restricted from investing in any securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities. Advisors considers investments in these securities to be consistent with the Fund’s ESG criteria.

The Fund also invests in certain asset-backed securities, mortgage-backed securities and other securities that represent interests in assets such as pools of mortgage loans, automobile loans or credit card receivables. These securities are typically issued by legal entities established specifically to hold assets and to issue debt obligations backed by those assets. Asset-backed or mortgage-backed securities are normally created or “sponsored” by banks or other institutions or by certain U.S. Government-sponsored enterprises (“GSEs”) such as the Federal National Mortgage Association (“Fannie Mae”) and the Federal Home Loan Mortgage Corporation (“Freddie Mac”). Advisors does not take into consideration whether the sponsor of an asset-backed security in which the Fund invests meets the ESG criteria or the Fund’s Impact framework. That is because asset-backed securities represent interests in pools of loans, and not of the ongoing business enterprise of the sponsor. It is therefore possible that the Fund could invest in an asset-backed or mortgage-backed security sponsored by a bank or other financial institution in which the Fund could not invest directly.

The Fund’s investments in mortgage-backed securities can include pass-through securities sold by private, governmental and government-related organizations and collateralized mortgage obligations (“CMOs”). Mortgage pass-through securities are created when mortgages are pooled together and interests in the pool are sold to investors. The cash flow from the underlying mortgages is “passed through” to investors in periodic principal and interest payments. CMOs are obligations that are fully collateralized directly or indirectly by a pool of mortgages from which payments of principal and interest are dedicated to the payment of principal and interest on the CMO.

The Board of Trustees of the Trust or a designated committee thereof (“Board of Trustees”) reviews the ESG criteria used to evaluate securities held by the Fund and the ESG vendor(s) that provide the data that help inform this criteria. Subject to Board of Trustees review, Advisors has the right to change the ESG vendor(s) at any time and to add to the number of vendors providing the ESG data.

Additionally, Advisors invests a portion of the Fund’s assets in fixed-income instruments taking into consideration the Impact framework as implemented by the Fund’s portfolio management team. As of March 31, 2024, these investments were 38.6% of the portfolio. These investments provide direct exposure to issuers and/or individual projects that Advisors, through its proprietary analysis, believes have the potential to have social or environmental benefits. Within this exposure to impact investments, the Fund seeks opportunities to invest in publicly traded fixed-income securities that finance initiatives in areas including affordable housing, community and economic development, renewable energy and climate change, and natural resources. These investments will be selected based on the same financial criteria used by Advisors in selecting the Fund’s other fixed-income investments. The portion of the Fund invested in accordance with the Impact framework is not additionally subject to ESG criteria. Advisors engages with certain issuers of investments deemed by Advisors to represent impact securities to communicate impact reporting preferences and encourage alignment with industry best practices regarding responsible investment.

Investing on the basis of ESG criteria and according to the Fund’s Impact framework is qualitative and subjective by nature. There can be no assurance that every Fund investment will meet ESG criteria or the Impact framework, or will do so at all times, or that the ESG criteria and the Impact framework or any judgment exercised by Advisors will reflect the beliefs or values of any particular investor.

The Fund may also use a trading technique called “mortgage rolls” or “dollar rolls” in which the Fund “rolls over” an investment in a mortgage-backed security before its settlement date in exchange for a similar security with a later settlement date.

The Fund may also engage in relative value trading, a strategy in which the Fund reallocates assets across different sectors and maturities. Relative value

trading is designed to enhance the Fund’s returns but increases the Fund’s portfolio turnover rate.

The Fund may purchase and sell futures, options, swaps, forwards and other fixed-income derivative instruments to carry out the Fund’s investment strategies. The Fund may also invest in foreign securities, including emerging markets fixed-income securities and non-dollar-denominated instruments. Under most circumstances, the Fund’s investments in fixed-income securities of foreign issuers constitute less than 40% of the Fund’s assets.

· ESG Criteria and Impact Risk—The risk that because the Fund’s ESG criteria and/or proprietary Impact framework exclude securities of certain issuers for nonfinancial reasons, the Fund may forgo some market opportunities available to funds that do not use these criteria.

· Interest Rate Risk (a type of Market Risk)—The risk that changes in interest rates can adversely affect the value or liquidity of, and income generated by, fixed-income investments. This risk is heightened to the extent the Fund invests in longer duration fixed-income investments and during periods when prevailing interest rates are changing. There is a risk that interest rates across the financial system may change, possibly significantly and/or rapidly. In general, changing interest rates, including rates that fall below zero, or a lack of market participants may lead to decreased liquidity and increased volatility in the fixed-income or debt markets, making it more difficult for the Fund to sell fixed-income investments. When interest rates change, the values of longer duration fixed-income securities usually change more than the values of shorter duration fixed-income securities. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. Other factors that may affect the value of debt securities include, but are not limited to, economic, political, public health, and other crises and responses by governments and companies to such crises.

· Prepayment Risk—The risk that, during periods of falling interest rates, borrowers may pay off their mortgage loans sooner than expected, forcing the Fund to reinvest the unanticipated proceeds at lower interest rates and resulting in a decline in income.

· Extension Risk—The risk that, during periods of rising interest rates, borrowers may pay off their mortgage loans later than expected, preventing the Fund from reinvesting principal proceeds at higher interest rates and resulting in less income than potentially available.

· Issuer Risk (often called Financial Risk)—The risk that an issuer’s earnings prospects, credit rating and overall financial position will deteriorate, causing a decline in the value of the issuer’s financial instruments over short or extended periods of time.

· Credit Risk (a type of Issuer Risk)—The risk that the issuer of fixed-income investments may not be able or willing, or may be perceived (whether by market participants, rating agencies, pricing services or otherwise) as not able or willing, to meet interest or principal payments when the payments become due.

· Credit Spread Risk—The risk that credit spreads (i.e., the difference in yield between securities that is due to differences in each security’s respective credit quality) may increase when market participants believe that bonds generally have a greater risk of default, which could result in a decline in the market values of the Fund’s debt securities.

· Income Volatility Risk—The risk that the level of current income from a portfolio of fixed-income investments may decline in certain interest rate environments.

· Market Volatility, Liquidity and Valuation Risk (types of Market Risk)—The risk that volatile or dramatic reductions in trading activity make it difficult for the Fund to properly value its investments and that the Fund may not be able to purchase or sell an investment at an attractive price, if at all.

· Fixed-Income Foreign Investment Risk—Investment in fixed-income securities or financial instruments of foreign issuers involves increased risks due to adverse issuer, political, regulatory, currency, market or economic developments as well as armed conflicts. These developments may impact the ability of a foreign debt issuer to make timely and ultimate payments on its debt obligations to the Fund or impair the Fund’s ability to enforce its rights against the foreign debt issuer. These risks are heightened in emerging or developing markets. Foreign investments may also have lower overall liquidity and be more difficult to value than investments in U.S. issuers. Foreign investments may also be subject to risk of loss because of more or less foreign government regulation, less public information, less stringent investor protections, and less stringent accounting, corporate governance, financial reporting and disclosure standards. Changes in the value of foreign currencies may make the return on an investment increase or decrease, unrelated to the quality or performance of the investment itself. The imposition of sanctions, exchange controls (including repatriation restrictions), confiscations, trade restrictions (including tariffs) and other restrictions by the United States or other governments may also negatively impact the Fund’s investments. Economic sanctions and other similar governmental actions or developments could, among other things, effectively restrict or eliminate the Fund’s ability to purchase or sell certain foreign securities or groups of foreign securities, and/or thus may make the Fund’s investments in such securities less liquid (or illiquid) or more difficult to

value. The type and severity of sanctions and other measures that may be imposed could vary broadly in scope, and their impact is impossible to predict.

· Active Management Risk—The risk that Advisors’ strategy, investment selection or trading execution may cause the Fund to underperform relative to the benchmark index or mutual funds with similar investment objectives and may not produce expected returns.

· Call Risk—The risk that, during periods of falling interest rates, an issuer may call (or repay) a fixed-income security prior to maturity, resulting in a decline in the Fund’s income.

· Mortgage Roll Risk—The risk that Advisors will not correctly predict mortgage prepayments and interest rates, which will diminish the Fund’s performance.

· Downgrade Risk—The risk that securities are subsequently downgraded should Advisors and/or rating agencies believe the issuer’s business outlook or creditworthiness has deteriorated.

· Non-Investment-Grade Securities Risk—Issuers of non-investment-grade securities, which are usually called “high-yield” or “junk bonds,” are typically speculative in nature, in weaker financial health and such securities can be harder to value and sell and their prices can be more volatile than more highly rated securities. While these securities generally have higher rates of interest, they also involve greater risk of default than do securities of a higher-quality rating. In times of unusual or adverse market, economic or political conditions, these securities may experience higher than normal default rates.

· Illiquid Investments Risk—The risk that illiquid investments may be difficult to sell for the value at which they are carried, if at all, or at any price within the desired time frame.

· Emerging Markets Risk—The risk of foreign investment often increases in countries with emerging markets or otherwise economically tied to emerging market countries. For example, these countries may have more unstable governments than developed countries, and their economies may be based on only a few industries. Emerging market countries may also have less stringent regulation of accounting, auditing, financial reporting and recordkeeping requirements, which would affect a Fund’s ability to evaluate potential portfolio companies. As a result, there could be less information available about issuers in emerging market countries, which could negatively affect Advisors’ ability to evaluate local companies or their potential impact on a Fund’s performance. Because their financial markets may be very small, share prices of financial instruments in emerging market countries may be volatile and difficult to determine. Financial instruments of issuers in these countries may have lower overall liquidity than those of issuers in more developed countries. In addition, foreign investors such as a Fund are subject to a variety of special restrictions in many emerging market countries.

Moreover, legal remedies for investors in emerging markets may be more limited, and U.S. authorities may have less ability to bring actions against bad actors in emerging market countries. The risks outlined above are often more pronounced in “frontier markets” in which the Fund may invest. Frontier markets are those emerging markets that are considered to be among the smallest, least mature and least liquid. These factors may make investing in frontier market countries significantly riskier than investing in other countries.

· U.S. Government Securities Risk—Securities issued by the U.S. Government or one of its agencies or instrumentalities may receive varying levels of support from the U.S. Government, which could affect the Fund’s ability to recover should they default. To the extent the Fund invests significantly in securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the securities of the U.S. Government or its agencies or instrumentalities in which the Fund invests may have a significant impact on the Fund’s performance.

· Derivatives Risk—The risks associated with investing in derivatives, including futures, options, swaps, forwards, and other fixed-income derivative instruments, and other similar instruments (referred to collectively as “derivatives”) may be different and greater than the risks associated with directly investing in the underlying securities and other instruments, and include leverage risk, market risk, counterparty risk, liquidity risk, operational risk and legal risk. The Fund may use more complex derivatives that might be particularly susceptible to liquidity, credit and counterparty risk. When investing in derivatives, the Fund may lose more than the principal amount invested.

· Portfolio Turnover Risk—Depending on market and other conditions, the Fund may experience high portfolio turnover, which may result in greater transactional expenses, such as brokerage commissions, bid-ask spreads, or dealer mark-ups, and capital gains (which could increase taxes and, consequently, reduce returns).

· Floating and Variable Rate Securities Risk—Floating and variable rate securities provide for a periodic adjustment in the interest rate paid on the securities. The rate adjustment intervals may be regular and range from daily up to annually, or may be based on an event, such as a change in the prime rate. Floating and variable rate securities may be subject to greater liquidity risk than other debt securities, meaning that there may be limitations on the Fund’s ability to sell the securities at any given time. Such securities also may lose value.

The following chart and table help illustrate some of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year. The bar chart shows the annual total returns of Class R6 of the Fund, before taxes, in each full calendar year since inception of Class R6. Because the expenses vary across share classes, the performance of Class R6 may vary from the other share classes. Below the bar chart are the best and worst returns of Class R6 for a calendar quarter during the full calendar-year periods covered by the bar chart. The performance table following the bar chart shows the Fund’s average annual total returns for Class A, Class I, Premier Class, Class R6 and Retirement Class over the applicable one-year, five-year, ten-year and since-inception periods ended December 31, 2023, and how those returns compare to those of the Fund’s benchmark index. In accordance with new regulatory requirements, the Fund has selected the Bloomberg U.S. Aggregate Bond Index, which represents a broad measure of market performance, and is generally representative of the market sectors or types of investments in which the Fund invests. After-tax performance is shown only for Class R6 shares, and after-tax returns for the other classes of shares will vary from the after-tax returns presented for Class R6 shares.

The returns shown below reflect previous agreements by Advisors to waive or reimburse the Fund for certain fees and expenses. Without these waivers and reimbursements, the returns of the Fund would have been lower. Past performance of the Fund (before and after taxes) is not necessarily an indication of how it will perform in the future. The benchmark index listed below is unmanaged, and you cannot invest directly in an index. The returns for the benchmark index reflect no deduction for fees, expenses or taxes.

For current performance information of each share class, including performance to the most recent month-end, please visit www.nuveen.com/performance or call 800-257-8787.

ANNUAL TOTAL RETURNS FOR CLASS R6 SHARES (%)^†

Nuveen Core Impact Bond Fund

^† The year-to-date return as of the most recent calendar quarter, which ended on June 30, 2024, was 0.38%.

Best quarter: 6.51%, for the quarter ended December 31, 2023. Worst quarter: -5.99%, for the quarter ended March 31, 2022.

The Fund seeks total return, primarily through current income.

The following tables describe the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund or other Nuveen mutual funds. More information about these and other discounts, as well as eligibility requirements for each share class, is available from your financial advisor and in “How You Can Buy and Sell Shares” on page 192 of the Fund’s Prospectus and “Purchase and Redemption of Fund Shares” on page 105 of the Fund’s Statement of Additional Information. In addition, more information about sales charge discounts and waivers for purchases of shares through specific financial intermediaries is set forth in the appendix to the Fund’s Prospectus entitled “Variations in Sales Charge Reductions and Waivers Available Through Certain Intermediaries.

The tables and examples below do not reflect any commissions that shareholders may be required to pay directly to their financial intermediaries when buying or selling Class I shares.

SHAREHOLDER FEES (fees paid directly from your investment)

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)