Summary Prospectus by Investment Company - Form 497K

Summary Prospectus

May 1, 2024

SunAmerica Series Trust

SA Fidelity Institutional AM® Real Estate Portfolio

(Class 1, Class 2 and Class 3 Shares)

SunAmerica Series Trust's Statutory Prospectus and Statement of Additional Information, each dated May 1, 2024, as amended and supplemented from time to time, and the most recent shareholder reports are incorporated into and made part of this Summary Prospectus by reference. The Portfolio is offered only to the separate accounts of certain affiliated and unaffiliated life insurance companies and to other mutual funds. This Summary Prospectus is not intended for use by other investors.

Before you invest, you may want to review SunAmerica Series Trust's Statutory Prospectus, which contains more information about the Portfolio and its risks. You can find the Statutory Prospectus and the above-incorporated information online at https://www.corebridgefinancial.com/getprospectus. You can also get this information at no cost by calling (800) 445-7862 or by sending an e-mail request to [email protected].

The Securities and Exchange Commission has not approved or disapproved these securities, nor has it determined that this Summary Prospectus is accurate or complete. It is a criminal offense to state otherwise.

Investment Goal

The Portfolio's investment goal is total return through a combination of growth and income.

Fees and Expenses of the Portfolio

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Portfolio. The table and the example below do not reflect the separate account fees charged in the variable annuity or variable life insurance policy ("Variable Contracts") in which the Portfolio is offered. If separate account fees were shown, the Portfolio's annual operating expenses would be higher. Please see your Variable Contract prospectus for more details on the separate account fees.

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

	Class 1	Class 2	Class 3
Management Fees	0.77%	0.77%	0.77%
Service (12b-1) Fees	None	0.15%	0.25%
Other Expenses	0.07%	0.07%	0.07%
Total Annual Portfolio Operating Expenses	0.84%	0.99%	1.09%

Expense Example

This Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem or hold all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio's operating expenses remain the same. The Example does

not reflect charges imposed by the Variable Contract. If the Variable Contract fees were reflected, the expenses would be higher. See the Variable Contract prospectus for information on such charges. Although your actual costs may be higher or lower, based on these assumptions and the net expenses shown in the fee table, your costs would be:

	1 Year	3 Years	5 Years	10 Years
Class 1	$86	$268	$466	$1,037
Class 2	101	315	547	1,213
Class 3	111	347	601	1,329

Portfolio Turnover

The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Portfolio's performance.

During the most recent fiscal year, the Portfolio's portfolio turnover rate was 38% of the average value of its portfolio.

Principal Investment Strategies of the Portfolio

The Portfolio attempts to achieve its goal by investing, under normal circumstances, at least 80% of assets in securities of companies principally engaged in the real estate industry and other real estate related investments.

The Portfolio's subadviser believes that rigorous, bottom-up, fundamental research is the most effective manner in which to identify real estate companies with the potential for higher than average growth rates and strong balance sheets that can be purchased at reasonable prices. This

bottom-up research is generated by a team of skilled analysts specifically dedicated to the U.S. real estate investment trust ("REIT") sector. The subadviser's investment philosophy is built upon the belief that security selection has a higher probability of repeatability and success in different market environments. Accurately forecasting companies' future cash flow growth can help drive strong returns and benchmark outperformance. Additionally, identifying stocks that are dislocated from the market on relative fundamental and valuation bases can also help generate returns.

The Portfolio is non-diversified, which means that it may invest its assets in a smaller number of issuers than a diversified portfolio. The Portfolio, from time to time, may have significant investments in one or more countries or in particular sectors.

Principal Risks of Investing in the Portfolio

As with any mutual fund, there can be no assurance that the Portfolio's investment goal will be met or that the net return on an investment in the Portfolio will exceed what could have been obtained through other investment or savings vehicles. Shares of the Portfolio are not bank deposits and are not guaranteed or insured by any bank, government entity or the Federal Deposit Insurance Corporation. If the value of the assets of the Portfolio goes down, you could lose money.

The following is a summary of the principal risks of investing in the Portfolio.

Equity Securities Risk. The Portfolio invests principally in equity securities and is therefore subject to the risk that stock prices will fall and may underperform other asset classes. Individual stock prices fluctuate from day-to-day and may decline significantly.

Real Estate Industry Risk. The Portfolio is subject to the risks associated with the direct ownership of real estate. These risks include declines in the value of real estate, risks related to general and local economic conditions, overbuilding and increased competition, increases in property taxes and operating expenses, changes in zoning laws, casualty or condemnation losses, fluctuations in rental income, changes in neighborhood values, changes in the appeal of properties to tenants and increases in interest rates. The Portfolio also could be subject to the risks of direct ownership as a result of a default on a debt security it may own. If the Portfolio has rental income or income from the disposition of real property, the receipt of such income may adversely affect its ability to retain its tax status as a regulated investment company. Most of the Portfolio's investments are, and

likely will continue to be, interests in REITs. REITs may be leveraged, which increases risk.

Non-Diversification Risk. The Portfolio is organized as a "non-diversified" fund. A non-diversified fund may invest a larger portion of assets in the securities of a single company than a diversified fund. By concentrating in a smaller number of issuers, the Portfolio's risk may be increased because the effect of each security on the Portfolio's performance is greater.

Sector or Industry Focus Risk. To the extent the Portfolio invests a significant portion of its assets in one or more sectors or industries at a time, the Portfolio will face a greater risk of loss due to factors affecting sectors or industries than if the Portfolio always maintained wide diversity among the sectors and industries in which it invests.

Issuer Risk. The value of a security may decline for a number of reasons directly related to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods and services.

Management Risk. The Portfolio is subject to management risk because it is an actively-managed investment portfolio. The Portfolio's portfolio managers apply investment techniques and risk analyses in making investment decisions, but there can be no guarantee that these decisions or the individual securities selected by the portfolio managers will produce the desired results.

Market Risk. The Portfolio's share price or the market as a whole can decline for many reasons or be adversely affected by a number of factors, including, without limitation: weakness in the broad market, a particular industry, or specific holdings; adverse political, regulatory or economic developments in the United States or abroad; changes in investor psychology; heavy institutional selling; military confrontations, war, terrorism and other armed conflicts, disease/virus outbreaks and epidemics; recessions; taxation and international tax treaties; currency, interest rate and price fluctuations; and other conditions or events. In addition, the subadviser's assessment of securities held in the Portfolio may prove incorrect, resulting in losses or poor performance even in a rising market.

Affiliated Fund Rebalancing Risk. The Portfolio may be an investment option for other mutual funds for which SunAmerica Asset Management, LLC ("SunAmerica") serves as investment adviser that are managed as "funds of funds." From time to time, the Portfolio may experience relatively large redemptions or investments due to the rebalancing of a fund of funds. In the event of such

redemptions or investments, the Portfolio could be required to sell securities or to invest cash at a time when it is not advantageous to do so.

Performance Information

The Portfolio's benchmark is the FTSE NAREIT Equity REITs Index. The subadviser believes that the FTSE NAREIT Equity REITs Index is representative of the investible universe.

The following bar chart illustrates the risks of investing in the Portfolio by showing changes in the Portfolio's performance from calendar year to calendar year and the table compares the Portfolio's average annual returns to those of the S&P 500® Index (a broad-based securities market index) and the FTSE NAREIT Equity REITs Index, which is relevant to the Portfolio because it has similar characteristics to the Portfolio's investment strategies.Fees and expenses incurred at the contract level are not reflected in the bar chart or table. If these amounts were reflected, returns would be less than those shown. Of course, past performance is not necessarily an indication of how the Portfolio will perform in the future.

FIAM LLC ("FIAM") assumed subadvisory duties of the Portfolio on October 1, 2013. Prior to October 1, 2013, Davis Selected Advisers, L.P. d/b/a Davis Advisors served as subadviser.

(Class 1 Shares)

During the period shown in the bar chart:

Highest Quarterly Return:	March 31, 2019	17.02%
Lowest Quarterly Return:	March 31, 2020	-21.85%
Year to Date Most Recent Quarter:	March 31, 2024	-0.33%

Average Annual Total Returns (For the periods ended December 31, 2023)

	1 Year	5 Years	10 Years
Class 1 Shares	14.02%	7.68%	7.43%
Class 2 Shares	13.91%	7.52%	7.28%
Class 3 Shares	13.86%	7.43%	7.17%
S&P 500® Index (reflects no deduction for fees, expenses or taxes)	26.29%	15.69%	12.03%
FTSE NAREIT Equity REITs Index (reflects no deduction for fees, expenses or taxes)	13.73%	7.39%	7.65%

Investment Adviser

The Portfolio's investment adviser is SunAmerica.

The Portfolio is subadvised by FIAM.

Portfolio Manager

Name and Title	Portfolio Manager of the Portfolio Since
Samuel Wald, CFA Portfolio Manager	2013

Purchases and Sales of Portfolio Shares

Shares of the Portfolios may only be purchased or redeemed through Variable Contracts offered by the separate accounts of participating life insurance companies and by other portfolios of the Trust and Seasons Series Trust. Shares of a Portfolio may be purchased and redeemed each day the New York Stock Exchange is open, at the Portfolio's net asset value determined after receipt of a request in good order.

The Portfolios do not have any initial or subsequent investment minimums. However, your insurance company may impose investment or account minimums. Please consult the prospectus (or other offering document) for your Variable Contract which may contain additional information about purchases and redemptions of Portfolio shares.

Tax Information

The Portfolios will not be subject to U.S. federal income tax so long as they qualify as regulated investment companies and distribute their income and gains each year to their shareholders. However, contractholders may be subject to U.S. federal income tax (and a U.S. federal Medicare tax of 3.8% that applies to net investment income, including

taxable annuity payments, if applicable) upon withdrawal from a Variable Contract. Contractholders should consult the prospectus (or other offering document) for the Variable Contract for additional information regarding taxation.

Payments to Broker-Dealers and
Other Financial Intermediaries

The Portfolios are not sold directly to the general public but instead are offered as an underlying investment option for Variable Contracts and to other portfolios of the Trust and