Nuveen Life Core Bond Fund

MAY 1, 2026, AS SUPPLEMENTED AUGUST 1, 2026

Ticker: TLBDX

This summary prospectus is designed to provide investors with key Fund information in a clear and concise format. Before you invest, you may want to review the Fund’s complete prospectus, which contains more information about the Fund and its risks. You can find the Fund’s prospectus, reports to shareholders and other information about the Fund online at www.tiaa.org/prospectus. You can also get this information at no cost by calling 800-223-1200 or by sending an email request to disclosure@tiaa.org. The Fund’s prospectus and statement of additional information, both dated May 1, 2026, are incorporated by reference into this summary prospectus and may be obtained, free of charge, at the website, phone number or e-mail address noted above.

Investment objective

The Fund seeks total return, primarily through current income.

Fees and expenses

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. The expenses shown do not reflect any separate account fees or expenses deducted under the variable annuity contracts or variable life insurance policies using the Fund as an underlying investment option.

SHAREHOLDER FEES (fees paid directly from your investment)

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

Example

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 duration noted in the table above. The example does not reflect the fees and expenses of any variable annuity contract or variable life insurance policy and the costs in the example would be higher if it did. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio turnover

The Fund pays transaction costs, such as commissions, as applicable, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs. 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 December 31, 2025, the Fund’s portfolio turnover rate was 86% of the average value of its portfolio.

Principal investment strategies

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-

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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 sub-adviser, Nuveen Asset Management, LLC (“Nuveen Asset Management”), 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 Nuveen Asset Management 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 December 31, 2025, the duration of the Fund’s benchmark index, the Bloomberg U.S. Aggregate Bond Index, was 5.98 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

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upon the ability of Nuveen Asset Management 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.

Principal investment risks

You could lose money over short or long periods by investing in this Fund. An investment in the Fund, due to the nature of the Fund’s portfolio holdings, typically is subject to the following principal investment risks:

· 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.

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· 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. Actual or perceived changes in economic, social, public health, financial or political conditions in general or that affect a particular type of investment, issuer, guarantor or counterparty can reduce the ability of the party to meet its obligations, which can affect the credit quality, liquidity and/or value of an investment.

· 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

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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 Nuveen Asset Management’s 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/or strategies and may not produce the desired results or 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 Nuveen Asset Management 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 Nuveen Asset Management 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

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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 risks of foreign investment often increases in countries with emerging markets or those 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. As a result, there could be less information available about issuers in emerging market countries, which could negatively affect Nuveen Asset Management’s 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 and may be more vulnerable to market manipulation. 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 enforce certain regulatory or legal obligations or otherwise bring actions against bad actors in emerging market 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.

· 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

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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. Derivatives used for hedging or risk management may not operate as intended, may expose the Fund to other risks, and may be insufficient to protect the Fund from the risks they were intended to hedge.

Please see the non-summary portion of the Prospectus for more detailed information about the risks described above.

Past performance

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 shares of the Fund during the preceding ten-year period. Below the bar chart are the best and worst returns for a calendar quarter during the same period. The performance table following the bar chart shows the Fund’s average annual total returns over the one-year, five-year, ten-year and since-inception periods (where applicable) ended December 31, 2025, and how those returns compare to those of the Fund’s broad-based securities market and benchmark index. For periods prior to August 1, 2026, Teachers Advisors, LLC (“Advisors”) served as investment adviser to the Fund. Returns do not reflect fees and expenses of any variable annuity or variable life insurance contract and would be lower if they did.

The returns shown below reflect previous agreements by Advisors, the Fund’s prior investment adviser, 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 is not necessarily an indication of how it will perform in the future. The broad-based securities market and benchmark index listed below is unmanaged, and you cannot invest directly in an index. The returns for the broad-based securities market and benchmark index reflect no deduction for fees, expenses or taxes.

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

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ANNUAL TOTAL RETURNS (%)

Nuveen Life Core Bond Fund

Best quarter: 6.52%, for the quarter ended December 31, 2023. Worst quarter: -5.97%, for the quarter ended March 31, 2022.

AVERAGE ANNUAL TOTAL RETURNS

For the Periods Ended December 31, 2025 ^†

Portfolio management

Investment Adviser. Nuveen Fund Advisors, LLC.

Sub-Adviser. Nuveen Asset Management, LLC.

Portfolio Managers.

Purchase and sale of Fund shares

Please contact the insurance company that issued your variable annuity or life insurance contract for more information on the purchase and sale of Fund shares.

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Tax information

Because the only shareholders of the Fund are the insurance companies offering the contracts, no discussion is included here about the federal income tax consequences at the shareholder level. The federal income tax consequences for purchases of a variable annuity or life insurance contract are described in the prospectus for such contracts.

Payments to insurance companies and broker-dealers and other financial intermediary compensation

The Fund is only available as an underlying investment for the contracts. The Fund and its distributor (and their related companies) may make payments to the sponsoring insurance company (or its affiliates) and to broker-dealers and other financial intermediaries for distribution and/or other services. These payments may be a factor that the insurance company considers in including the Fund as an underlying investment option in the variable contract. Payments to broker-dealers and other financial intermediaries may create a conflict of interest by influencing the broker-dealer or other financial intermediary to recommend a variable product and the Fund over another investment. Ask your financial adviser or visit the website of the insurance company or the financial intermediary for more information. The disclosure document for your variable contract may contain additional information about these payments.

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