Summary Prospectus by Investment Company (Form 497K)

SUMMARY PROSPECTUS

JULY 29, 2025

SUNAMERICA SERIES TRUST

SA GOLDMAN SACHS GOVERNMENT AND QUALITY BOND PORTFOLIO

(FORMERLY, SA WELLINGTON GOVERNMENT AND QUALITY BOND PORTFOLIO)

(CLASS 1, CLASS 2 AND CLASS 3 SHARES)

Investment Goal

The Portfolio’s investment goal is to seek a high degree of income and total return, consistent with safety of principal and the high credit quality of U.S. Government securities.

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)

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 (except that the Example incorporates any applicable fee waiver and/or expense limitation arrangements for only the first year). 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:

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 90% of the average value of its portfolio.

Principal Investment Strategies of the Portfolio

The Portfolio’s principal investment strategy is to invest, under normal circumstances, at least 80% of net assets in obligations issued, guaranteed or insured by the U.S. Government, its agencies or instrumentalities and in high quality fixed income securities (rated AA- or better by S&P Global Ratings or Aa3 or better by Moody’s Investors Service, Inc. or its equivalent by any other nationally recognized statistical rating organization).

SA GOLDMAN SACHS GOVERNMENT AND QUALITY BOND PORTFOLIO

(FORMERLY, SA WELLINGTON GOVERNMENT AND QUALITY BOND PORTFOLIO)

U.S. Government securities include agency issued adjustable rate and fixed rate mortgage-backed securities and other mortgage-related securities (“Agency Mortgage-Backed Securities”) and repurchase agreements collateralized by such securities. The Portfolio may invest in fixed income securities of any maturity.

The Portfolio may gain exposure to Agency Mortgage-Backed Securities through several methods, including by utilizing to-be-announced (“TBA”) agreements in Agency Mortgage-Backed Securities or through the use of reverse repurchase agreements. TBA agreements for Agency Mortgage-Backed Securities are standardized contracts for future delivery of fixed-rate mortgage pass-through securities in which the exact mortgage pools to be delivered are not specified until shortly before settlement. A reverse repurchase agreement enables the Portfolio to gain exposure to specified pools of Agency Mortgage-Backed Securities by purchasing them on a forward settling basis and using the proceeds of the reverse repurchase agreement to settle the trade.

The Portfolio also intends to invest in derivatives, including, but not limited to, futures, swaps and options on swaps, which are used primarily to hedge the Portfolio’s portfolio risks, manage the Portfolio’s duration and/or gain exposure to certain fixed income securities.

The Portfolio may also implement short positions and may do so by using swaps or futures, TBA agreements in Agency Mortgage-Backed Securities, or through short sales of any instrument that the Portfolio may purchase for investment. For example, the Portfolio may enter into a futures contract pursuant to which it agrees to sell an asset (that it does not currently own) at a specified price at a specified point in the future. This gives the Portfolio a short position with respect to that asset. The Portfolio may utilize short positions to implement macro views on securities valuations, long-term views on relative value or short-term views on security mispricings, as well as any other views the subadviser deems appropriate. For example, the Portfolio may enter into a TBA agreement to sell an Agency Mortgage-Backed Security that it believes will underperform. The Portfolio will benefit from a short position to the extent the asset decreases in value (and will be harmed to the extent the asset increases in value) between the time it enters into the futures contract and the agreed date of sale. Alternatively, the Portfolio may sell an instrument (e.g., a bond, or a futures contract) it does not own in anticipation of a decline in the market value of the instrument and then borrow the instrument to make delivery to the buyer. In these transactions, the Portfolio is obligated to replace the instrument borrowed by purchasing it at the market price at the time of replacement.

The Portfolio’s net assets may also be invested in privately issued adjustable rate and fixed rate mortgage-backed

securities and other mortgage-related securities (such as commercial mortgage-backed securities and non-agency residential mortgage-backed securities), asset-backed securities, collateralized loan obligations, mortgage dollar rolls, corporate securities, municipal securities, floating and variable rate obligations, when-issued securities and forward commitments, short term investments and bank obligations. The Portfolio may use an active trading strategy to achieve its objective.

100% of the Portfolio’s portfolio will be invested in U.S. dollar-denominated securities.

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.

U.S. Government Obligations Risk. U.S. Treasury obligations are backed by the “full faith and credit” of the U.S. Government and generally have negligible credit risk. Securities issued or guaranteed by federal agencies or authorities and U.S. Government sponsored instrumentalities or enterprises may or may not be backed by the full faith and credit of the U.S. Government. For example, securities issued by the Federal Home Loan Mortgage Corporation, the Federal

National Mortgage Association and the Federal Home Loan Banks are neither insured nor guaranteed by the U.S. Government; these securities may be supported only by the ability to borrow from the U.S. Treasury or by the credit of the issuing agency, authority, instrumentality or enterprise and, as a result, are subject to greater credit risk than securities issued or guaranteed by the U.S. Treasury.

Bonds Risk. The value of your investment in the Portfolio may go up or down in response to changes in interest rates or defaults (or even the potential for future defaults) by bond issuers. Fixed income securities may be subject to volatility due to changes in interest rates.

Interest Rate Risk. Fixed income securities may be subject to volatility due to changes in interest rates. The value of fixed-income securities may decline when interest rates go up or increase when interest rates go down. The interest earned on fixed-income securities may decline when interest rates go down or increase when interest rates go up. Duration is a

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measure of interest rate risk that indicates how price-sensitive a bond is to changes in interest rates. Longer-term and lower coupon bonds tend to be more sensitive to changes in interest rates. For example, a bond with a duration of three years will decrease in value by approximately 3% if interest rates increase by 1%. Changing interest rates may have unpredictable effects on markets, may result in heightened market volatility, and could negatively impact the Portfolio’s performance. Any future changes in monetary policy made by central banks and/or their governments are likely to affect the level of interest rates.

Credit Risk. The risk that an issuer will default on interest or principal payments. The Portfolio could lose money if the issuer of a debt security is unable or perceived to be unable to pay interest or to repay principal when it becomes due. Various factors could affect the issuer’s actual or perceived willingness or ability to make timely interest or principal payments, including changes in the issuer’s financial condition or in general economic conditions. Debt securities backed by an issuer’s taxing authority may be subject to legal limits on the issuer’s power to increase taxes or otherwise raise revenue, or may be dependent on legislative appropriation or government aid. Certain debt securities are backed only by revenues derived from a particular project or source, rather than by an issuer’s taxing authority, and thus may have a greater risk of default. Credit risk applies to most debt securities, but is generally not a factor for obligations backed by the “full faith and credit” of the U.S. Government.

An issuer with a lower credit rating will be more likely than a higher rated issuer to default or otherwise become unable to honor its financial obligations. Issuers with low credit ratings typically issue junk bonds. In addition to the risk of default, junk bonds may be more volatile, less liquid, more difficult to value and more susceptible to adverse economic conditions or investor perceptions than other bonds.

Mortgage- and Asset-Backed Securities Risk. Mortgage- and asset-backed securities represent interests in “pools” of mortgages or other assets, including consumer loans or receivables held in trust. Asset-backed securities issued by trusts and special purpose corporations are backed by a pool of assets, such as credit card or automobile loan receivables representing the obligations of a number of different parties. Mortgage-backed securities directly or indirectly provide funds for mortgage loans made to residential home buyers. These include securities that represent interests in pools of mortgage loans made by lenders such as commercial banks, savings and loan institutions, mortgage bankers and others. They include mortgage pass-through securities, collateralized mortgage obligations (“CMOs”), commercial mortgage-backed securities, mortgage dollar rolls, CMO residuals, stripped mortgage-backed securities, non-agency residential mortgage-backed securities and other securities that directly or

indirectly represent a participation in, or are secured by and payable from, mortgage loans or real property. The characteristics of these mortgage-backed and asset-backed securities differ from traditional fixed-income securities.

The Portfolio may invest in both agency and non-agency mortgage-backed securities. Unlike agency mortgage-backed securities which are issued and guaranteed by government-sponsored enterprises or agencies, non-agency mortgage-backed securities are issued by non-governmental issuers and therefore have no direct or indirect government guarantees of payment. Non-agency mortgage-backed securities may be subject to liquidity risk, credit risk, default risk, subordination risk, and interest rate risk. Both agency and non-agency mortgage-backed securities are also subject to “prepayment risk” and “extension risk.” Prepayment risk is the risk that, when interest rates fall, certain types of obligations will be paid off by the obligor more quickly than originally anticipated and the Portfolio may have to invest the proceeds in securities with lower yields. Extension risk is the risk that, when interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these securities to fall. Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain mortgage-backed securities. These securities also are subject to risk of default on the underlying mortgage, particularly during periods of economic downturn.

Derivatives Risk. A derivative is any financial instrument whose value is based on, and determined by, another security, index, rate or benchmark (i.e., stock options, futures, caps, floors, etc.). To the extent a derivative contract is used to hedge another position in the Portfolio, the Portfolio will be exposed to the risks associated with hedging described below. To the extent an option, futures contract, swap, or other derivative is used with the goal of enhancing return, rather than as a hedge, the Portfolio will be directly exposed to the risks of the contract. Unfavorable changes in the value of the underlying security, index, rate or benchmark may cause sudden losses. Gains or losses from the Portfolio’s use of derivatives may be substantially greater than the amount of the Portfolio’s investment. Certain derivatives have the potential for unlimited loss. Derivatives are also associated with various other risks, including market risk, leverage risk, hedging risk, counterparty risk, valuation risk, regulatory risk, illiquidity risk and interest rate risk. The primary risks associated with the Portfolio’s use of derivatives are market risk, counterparty risk and hedging risk.

Futures Risk. Futures are contracts involving the right to receive or the obligation to deliver assets or money depending on the performance of one or more underlying assets, instruments or a market or economic index. A futures contract is an exchange-traded legal contract to buy or sell a standard quantity and quality of a commodity, financial instrument,

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index, etc. at a specified future date and price. A futures contract is considered a derivative because it derives its value from the price of the underlying commodity, security or financial index. The prices of futures contracts can be volatile and futures contracts may lack liquidity. In addition, there may be imperfect or even negative correlation between the price of a futures contract and the price of the underlying commodity, security or financial index.

Swaps Risk. Swap agreements are two party contracts entered into primarily by institutional investors for periods ranging from a few weeks to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments, which may be adjusted for an interest factor. In addition to the risks generally applicable to derivatives, swap agreements involve the risk that the party with whom the Portfolio has entered into the swap will default on its obligation to pay the Portfolio and the risk that the Portfolio will not be able to meet its obligations to pay the other party to the agreement.

Swaptions Risk. A swaption is an options contract on a swap agreement. The buyer of a swaption pays a non-refundable premium for the option and obtains the right, but not the obligation, to enter into an underlying swap on agreed-upon terms. The seller of a swaption, in exchange for the premium, becomes obligated (if the option is exercised) to enter into the underlying swap on agreed-upon terms. Swaptions enable the Portfolio to purchase exposure that is significantly greater than the premium paid. Consequently, the value of swaptions can be volatile, and a small investment in swaptions can have a large impact on the performance of the Portfolio. The Portfolio risks losing all or part of the cash paid (premium) for purchasing swaptions. Additionally, the value of the option may be lost if the portfolio managers fail to exercise such option at or prior to its expiration.

Reverse Repurchase Agreement Risk. Reverse repurchase agreements involve the sale of securities held by a Portfolio with an agreement to repurchase the securities at an agreed-upon price, date and interest payment. Reverse repurchase agreements involve the risk that the other party may fail to return the securities in a timely manner or at all. The Portfolio could lose money if it is unable to recover the securities and the value of the collateral held by the Portfolio, including the value of the investments made with cash collateral, is less than the value of securities. These events could also trigger adverse tax consequences to the Portfolio.

Leverage Risk. The Portfolio may engage in certain transactions that may expose it to leverage risk. The use of leverage may cause the Portfolio to liquidate portfolio positions at inopportune times in order to meet regulatory asset coverage requirements, fulfill leverage contract terms or for other

reasons. Leveraging, including borrowing, tends to increase the Portfolio’s exposure to market risk, interest rate risk or other risks, and thus may cause the Portfolio to be more volatile than if the Portfolio had not utilized leverage.

Call Risk. The risk that an issuer will exercise its right to pay principal on a debt obligation (such as a mortgage-backed security or convertible security) that is held by the Portfolio earlier than expected. This may happen when there is a decline in interest rates. Under these circumstances, the Portfolio may be unable to recoup all of its initial investment and will also suffer from having to reinvest in lower-yielding securities.

Collateralized Loan Obligation Risk. A collateralized loan obligation is a trust typically collateralized by a pool of loans, which may include, among others, domestic and foreign senior secured loans, senior unsecured loans, and subordinate corporate loans, including loans that may be rated below investment grade or equivalent unrated loans. The cash flows from the trust are split into two or more portions, called tranches, varying in risk and yield. The riskiest portion is the “equity” tranche which bears the bulk of defaults from the bonds or loans in the trust and serves to protect the other, more senior tranches from default in all but the most severe circumstances. Because it is partially protected from defaults, a senior tranche from a collateralized loan obligation trust typically has higher ratings and lower yields than its underlying securities, and can be rated investment grade. Despite the protection from the equity tranche, collateralized loan obligation tranches can experience substantial losses due to actual defaults, increased sensitivity to defaults due to collateral default and disappearance of protecting tranches, market anticipation of defaults, as well as aversion to collateralized loan obligation securities as a class.

Short Position Risk. Because the Portfolio’s potential loss on a short position arises from increases in the value of the asset sold short, the Portfolio will incur a loss on a short position, which is theoretically unlimited, if the price of the asset sold short increases from the short sale price. The counterparty to a short position or other market factors may prevent the Portfolio from closing out a short position at a desirable time or price and may reduce or eliminate any gain or result in a loss. In a rising market, the Portfolio’s short positions will cause the Portfolio to underperform the overall market and its peers that do not engage in shorting. If the Portfolio holds both long and short positions, and both positions decline simultaneously, the short positions will not provide any buffer (hedge) from declines in value of the Portfolio’s long positions. Certain types of short positions involve leverage, which may exaggerate any losses, potentially more than the actual cost of the investment, and will increase the volatility of the Portfolio’s returns.

Municipal Securities Risk. Municipal securities are subject to the risk that litigation, legislation or other political events,

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local business or economic conditions, or the bankruptcy of the issuer could have a significant effect on an issuer’s ability to make payments of principal and/or interest.

Floating Rate Securities Risk. Floating rate securities reset whenever there is a change in a specified index rate. In most cases, these reset provisions reduce the impact of changes in market interest rates on the value of the security. However, the value of these securities may decline if their interest rates do not rise as much, or as quickly, as other interest rates. Conversely, these securities will not generally increase in value if interest rates decline. The absence of an active market for these securities could make it difficult for the Portfolio to dispose of them if the issuer defaults.

Variable and floating rate obligations normally will involve industrial development or revenue bonds which provide that the rate of interest is set as a specific percentage of a designated base rate, such as rates on Treasury Bonds or Bills or the prime rate at a major commercial bank, and that a bondholder can demand payment of the obligations on behalf of the Portfolio on short notice at par plus accrued interest, which amount may be more or less than the amount the bondholder paid for them. The maturity of floating or variable rate obligations (including participation interests therein) is deemed to be the longer of (i) the notice period required before the Portfolio is entitled to receive payment of the obligation upon demand, or (ii) the period remaining until the obligation’s next interest rate adjustment. If not redeemed by the Portfolio through the demand feature, the obligations mature on a specified date which may range up to thirty years from the date of issuance.

Roll Transactions Risk. Roll transactions involve the sale of mortgage or other asset-backed securities with the commitment to purchase substantially similar (same type, coupon and maturity) but not identical securities on a specified future date. Roll transactions involve certain risks, including the following: if the broker-dealer to whom the Portfolio sells the security becomes insolvent, the Portfolio’s right to purchase or repurchase the security subject to the dollar roll may be restricted and the instrument that the Portfolio is required to repurchase may be worth less than an instrument that the Portfolio originally held. Successful use of roll transactions will depend upon the subadviser’s ability to predict correctly interest rates and, in the case of mortgage dollar rolls, mortgage prepayments. For these reasons, there is no assurance that dollar rolls can be successfully employed.

When-Issued Securities, Delayed Delivery and Forward Commitment Transactions Risk. When-issued and delayed delivery securities involve the risk that the security the Portfolio buys will lose value prior to its delivery. There also is the risk that the security will not be issued or that the other party to the transaction will not meet its obligation. If this

occurs, the Portfolio may lose both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.

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 social, political, regulatory or economic developments in the United States or abroad; changes in investor psychology; technological disruptions; heavy institutional selling; military confrontations, war, terrorism and other armed conflicts, trade wars and sanctions, 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.

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.

Active Trading Risk. The Portfolio may engage in frequent trading of securities to achieve its investment goal. Active trading may result in high portfolio turnover and correspondingly greater brokerage commissions and other transaction costs, which will be borne directly by the Portfolio and could affect its performance. During periods of increased market volatility, active trading may be more pronounced.

Performance Information

As a result of a reorganization which occurred on November 8, 2021 (the “Reorganization”), the Portfolio acquired all of the assets and liabilities of the SA Wellington Government and Quality Bond Portfolio (the “Predecessor Portfolio”), a series of Anchor Series Trust. The performance information below is based on the performance of the Predecessor Portfolio for periods prior to the date of the Reorganization. The Predecessor Portfolio had the same investment goal, strategies, portfolio management team and contractual fees and expenses as the Portfolio as of the date of the Reorganization. As a result, the performance of the Portfolio would have been substantially similar to that of the Predecessor Portfolio.

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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 Bloomberg U.S. Aggregate Bond Index (a broad-based securities market index), Bloomberg U.S. Aggregate A or Better Index, and Bloomberg U.S. Government/Mortgage Index. Effective July 28, 2025, the Bloomberg U.S. Government/Mortgage Index will replace the Bloomberg U.S. Aggregate A or Better Index as one of the performance benchmarks against which the Portfolio measures its performance. Portfolio management believes that the Bloomberg U.S. Government/Mortgage Index is more representative of the securities in which the Portfolio invests. The Portfolio’s returns prior to July 28, 2025, as reflected in the bar chart and table, are the returns of the Portfolio when it followed a different investment objective and different investment strategies under the name “SA Wellington Government and Quality Bond Portfolio.” 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.

Goldman Sachs Asset Management L.P. (“GSAM”) assumed subadvisory duties of the Portfolio on July 28, 2025. Prior to July 28, 2025, Wellington Management Company LLP subadvised the Portfolio.

(Class 1 Shares)

During the period shown in the bar chart:

Average Annual Total Returns (For the periods ended December 31, 2024)

Investment Adviser

The Portfolio’s investment adviser is SunAmerica Asset Management, LLC.

The Portfolio is subadvised by GSAM.

Portfolio Manager

Purchases and Sales of Portfolio Shares

Shares of the Portfolio 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 the 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.

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The Portfolio does 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 the Portfolio’s shares.

Tax Information

The Portfolio will not be subject to U.S. federal income tax so long as it qualifies as a regulated investment company and distributes its income and gains each year to its 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 Portfolio is not sold directly to the general public but instead is offered as an underlying investment option for Variable Contracts and to other portfolios of the Trust and Seasons Series Trust. The Portfolio and its related companies may make payments to the sponsoring insurance company (or its affiliates) for distribution and/or other services. These payments may create a conflict of interest as they may be a factor that the insurance company considers in including the Portfolio as an underlying investment option in the Variable Contract. The prospectus (or other offering document) for your Variable Contract may contain additional information about these payments.