FST Institutional Shares:    FIRXX

Before you invest, you may want to review the Goldman Sachs Financial Square Federal Instruments Fund’s (the “Fund”) Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s Prospectus and other information about the Fund, including the Statement of Additional Information (“SAI”) and most recent annual reports to shareholders, online at www.gsamfunds.com/summaries. You can also get this information at no cost by calling 800-621-2550 or by sending an e-mail request to gs-funds-document-requests@gs.com. The Fund’s Prospectus and SAI, both dated December 29, 2015, are incorporated by reference into this Summary Prospectus.

INVESTMENT OBJECTIVE

The Fund seeks to maximize current income to the extent consistent with the preservation of capital and the maintenance of liquidity by investing exclusively in high quality money market instruments.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

	FST      Institutional      Shares
Maximum Sales Charge (Load) Imposed on Purchases	None
Maximum Deferred Sales Charge (Load)	None
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fees	None
Exchange Fees	None

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

	FST Institutional Shares
Management Fees		0.21	%
Other Expenses1		0.12	%
Total Annual Fund Operating Expenses		0.33	%
Fee Waiver and Expense Limitation2		(0.13	)%
Total Annual Fund Operating Expenses After Fee Waiver and Expense Limitation		0.20	%

¹ The Fund’s “Other Expenses” have been estimated to reflect expenses expected to be incurred during the first fiscal year.

² The Investment Adviser has agreed to: (i) not impose a portion of the Management Fee equal annually to 0.025% of the Fund’s average daily net assets; and (ii) reduce or limit “Other Expenses” (excluding acquired fund fees and expenses, transfer agency fees and expenses, taxes, interest, brokerage fees, shareholder meeting, litigation, indemnification, and extraordinary expenses) to 0.014% of the Fund’s average daily net assets. These arrangements will remain in effect through at least December 29, 2016 and prior to such date the Investment Adviser may not terminate the arrangements without the approval of the Board of Trustees.

EXPENSE EXAMPLE

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

The Example assumes that you invest $10,000 in FST Institutional Shares of the Fund for the time periods indicated and then redeem all of your FST Institutional 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 remain the same (except that the Example incorporates the fee waiver and expense limitation arrangements for only the first year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years
FST Institutional Shares	$        20	$        93

PRINCIPAL STRATEGY

The Fund pursues its investment objective by investing only in “government securities,” as such term is defined in or interpreted under the Investment Company Act of 1940, as amended (“Investment Company Act”), the interest from which is generally exempt from state income taxation. “Government securities” generally are securities issued or guaranteed by the United States or certain U.S. government agencies or instrumentalities (“U.S. Government Securities”).

2        SUMMARY PROSPECTUS — GOLDMAN SACHS FINANCIAL SQUARE FEDERAL INSTRUMENTS FUND — FST INSTITUTIONAL SHARES

The Fund intends to be a “government money market fund,” as such term is defined in or interpreted under Rule 2a-7 under the Investment Company Act. “Government money market funds” are money market funds that invest at least 99.5% of their assets in cash, U.S. Government Securities, and/or repurchase agreements that are collateralized fully. “Government money market funds” are exempt from requirements that permit money market funds to impose a “liquidity fee” and/or “redemption gate.”

The Fund’s securities are valued using the amortized cost method as permitted by Rule 2a-7 under the Investment Company Act. Under Rule 2a-7, the Fund may invest only in U.S. dollar-denominated securities that are determined to present minimal credit risk and meet certain other criteria, including conditions relating to maturity, portfolio diversification, portfolio liquidity and credit quality. The Fund seeks to maintain a stable net asset value (“NAV”) of $1.00 per share.

PRINCIPAL RISKS OF THE FUND

You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation (“FDIC”) or any other government agency. The Fund’s sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time. The Fund should not be relied upon as a complete investment program. There can be no assurance that the Fund will achieve its investment objective.

Credit/Default Risk. An issuer or guarantor of a security held by the Fund may default on its obligation to pay interest and repay principal or default on any other obligation. Additionally, the credit quality of securities may deteriorate rapidly, which may impair the Fund’s liquidity and cause significant NAV deterioration.

Interest Rate Risk. When interest rates increase, the Fund’s yield will tend to be lower than prevailing market rates, and the market value of its securities or instruments may also be adversely affected. The risks associated with increasing interest rates are heightened given that interest rates are near historic lows, but are expected to increase in the future with unpredictable effects on the markets and the Fund’s investments. A low interest rate environment poses additional risks to the Fund, because low yields on the Fund’s portfolio holdings may have an adverse impact on the Fund’s ability to provide a positive yield to its shareholders, pay expenses out of Fund assets, or, at times, maintain a stable $1.00 share price.

Large Shareholder Transactions Risk. The Fund may experience adverse effects when certain large shareholders purchase or redeem large amounts of shares of the Fund. Such large shareholder redemptions may cause the Fund to sell portfolio securities at times when it would not otherwise do so, which may negatively impact the Fund’s NAV and liquidity. Similarly, large Fund share purchases may adversely affect the Fund’s performance to the extent that the Fund is delayed in investing new cash and is required to maintain a larger cash position than it ordinarily would. These transactions may also accelerate the realization of taxable income to shareholders if such sales of investments resulted in gains, and may also increase transaction costs. In addition, a large redemption could result in the Fund’s current expenses being allocated over a smaller asset base, leading to an increase in the Fund’s expense ratio.

Liquidity Risk. The Fund may make investments that are illiquid or that may become less liquid in response to market developments or adverse investor perceptions. Illiquid investments may be more difficult to value. The liquidity of portfolio securities can deteriorate rapidly due to credit events affecting issuers or guarantors, such as a credit rating downgrade, or due to general market conditions or a lack of willing buyers. An inability to sell one or more portfolio positions, or selling such positions at an unfavorable time and/or under unfavorable conditions, can adversely affect the Fund’s ability to maintain a stable $1.00 share price. Liquidity risk may also refer to the risk that the Fund will not be able to pay redemption proceeds within the allowable time period because of unusual market conditions, an unusually high volume of redemption requests, or other reasons. Liquidity risk may be the result of, among other things, the reduced number and capacity of traditional market participants to make a market in fixed income securities or the lack of an active market. The potential for liquidity risk may be magnified by a rising interest rate environment or other circumstances where investor redemptions from money market and other fixed income mutual funds may be higher than normal, potentially causing increased supply in the market due to selling activity.

Market Risk. The market value of the securities in which the Fund invests may go up or down in response to the prospects of individual companies, particular sectors or governments and/or general economic conditions throughout the world due to increasingly interconnected global economies and financial markets.

Regulatory Risk. The Securities and Exchange Commission (“SEC”) recently adopted changes to the rules that govern money market funds. These changes will: (1) permit (and, under certain circumstances, require) money market funds to impose a “liquidity fee” (up to 2%) or “redemption gate” that temporarily restricts redemptions from the funds, if weekly liquidity levels fall below the required regulatory threshold, and (2) require “institutional” money market funds to operate with a floating NAV rounded to the fourth decimal place. These changes, which have a compliance date of October 14, 2016, may affect the Fund’s investment strategies, operations and/or return potential. As of the date of this Prospectus, the Investment Adviser is evaluating the potential impact of these changes. Shareholders will be given notice of further developments as appropriate.

Stable NAV Risk. The Fund may not be able to maintain a stable $1.00 share price at all times. If any money market fund fails to maintain a stable NAV (or if there is a perceived threat of such a failure), other money market funds, including the Fund, could be subject to increased redemption activity, which could adversely affect the Fund’s NAV. Shareholders of the Fund should not rely on or expect the Investment Adviser or an affiliate to purchase

3        SUMMARY PROSPECTUS — GOLDMAN SACHS FINANCIAL SQUARE FEDERAL INSTRUMENTS FUND — FST INSTITUTIONAL SHARES

distressed assets from the Fund, make capital infusions into the Fund, enter into capital support agreements with the Fund or take other actions to help the Fund maintain a stable $1.00 share price.

U.S. Government Securities Risk. The U.S. government may not provide financial support to U.S. government agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Certain U.S. Government Securities, including securities issued by the Federal National Mortgage Association (“Fannie Mae”), Federal Home Loan Mortgage Corporation (“Freddie Mac”) and Federal Home Loan Banks, are neither issued nor guaranteed by the U.S. Treasury and, therefore, are not backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. Government Securities held by the Fund may greatly exceed their current resources, including any legal right to support from the U.S. Treasury. It is possible that issuers of U.S. Government Securities will not have the funds to meet their payment obligations in the future.

PERFORMANCE

As the Fund had not operated for a full calendar year as of the date of the Prospectus, there is no performance information quoted for the Fund. Updated performance information is available at no cost at www.gsamfunds.com/performance or by calling the appropriate phone number on the back cover of the Prospectus.

PORTFOLIO MANAGEMENT

Goldman Sachs Asset Management, L.P. is the investment adviser for the Fund (the “Investment Adviser” or “GSAM”).

BUYING AND SELLING FUND SHARES

Generally, FST Institutional Shares may be purchased only through certain banks, brokers, registered investment advisers and other financial institutions authorized to receive such orders (“Authorized Institutions”) that have agreed to provide administration and personal account maintenance services to their customers who are the beneficial owners of FST Institutional Shares. The minimum initial investment requirement imposed upon Authorized Institutions for the purchase of FST Institutional Shares is generally $10 million, and there is no minimum imposed upon additional investments. Authorized Institutions may, however, impose a minimum amount for initial and additional investments in FST Institutional Shares, and may establish other requirements such as a minimum account balance.

You may purchase and redeem (sell) shares of the Fund on any business day through an Authorized Institution.

TAX INFORMATION

The Fund’s distributions are taxable, and will be taxed as ordinary income or capital gains, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account. Investments through tax-deferred arrangements may become taxable upon withdrawal from such arrangements.

PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL  INTERMEDIARIES

If you purchase the Fund through an Authorized Institution, the Fund and/or its related companies may pay the Authorized Institution for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the Authorized Institution and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Authorized Institution’s website for more information.

4        SUMMARY PROSPECTUS — GOLDMAN SACHS FINANCIAL SQUARE FEDERAL INSTRUMENTS FUND — FST INSTITUTIONAL SHARES

FSINSSUM10-15