State Street Institutional U.S. Government Money Market Fund

Investment Objective

The investment objective of the State Street Institutional U.S. Government Money Market Fund (the “U.S. Government Fund” or sometimes referred to in context as the “Fund”) is to seek to maximize current income, to the extent consistent with the preservation of capital and liquidity and the maintenance of a stable $1.00 per share net asset value (“NAV”).

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy, hold, and sell shares of the U.S. Government Fund (“Fund Shares”). You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street U.S. Government Money Market Portfolio (the “U.S. Government Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

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

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses1	0.09%
Total Annual Fund Operating Expenses1,2	0.14%

“Other Expenses” and “Total Annual Fund Operating Expenses” have been restated to reflect current fees.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), and its affiliates, may voluntarily reduce all or a portion of their fees and/or reimburse expenses of the Fund or a share class to the extent necessary to maintain a certain minimum net yield, which may vary from time to time and from share class to share class within the Fund, in SSGA FM's sole discretion (any such waiver or reimbursement of expenses being referred to herein as a “Voluntary Reduction”), or a yield below a specified level, which may vary from time to time in the Adviser's sole discretion. The Fund has agreed, subject to certain limitations, to reimburse the Adviser and its affiliates for the full dollar amount of any Voluntary Reduction incurred beginning on May 1, 2020. During the fiscal year ended December 31, 2023, the Adviser and its affiliates did not waive fees or reimburse expenses under the Voluntary Reduction. Each of the Adviser and its affiliates may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from the Fund. Any future reimbursement by the Fund of the Voluntary Reduction would increase the Fund's expenses and may reduce the Fund's yield during such period. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that the Fund will be able to avoid a negative yield.

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 the Fund for the time periods indicated, and then sell or hold all of your Fund 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 year	3 years	5 years	10 years
$14	$45	$79	$179

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less, with the exception of certain floating rate securities that may have final maturities longer than 397 days but use maturity shortening provisions to meet the 397 day requirement, and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

Obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, such as U.S. Treasury securities and securities issued by the Government National Mortgage Association (“GNMA”), which are backed by the full faith and credit of the United States;

•

Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and

•

Repurchase agreements collateralized by U.S. government securities.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the U.S. Government Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Principal Risks

The Fund is subject to the following risks. 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 subject to investment risks, including possible loss of principal, is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (“FDIC”) or any other government agency. The Fund's sponsor is not required to reimburse the Fund for losses, and you should not expect that the sponsor will provide financial support to the Fund at any time, including during periods of market stress. Certain risks relating to instruments and strategies used in the management of the Fund are placed first. The significance of any specific risk to an investment in the Fund will vary over time, depending on the composition of the Fund's portfolio, market conditions, and other factors. You should read all of the risk information presented below carefully, because any one or more of these risks may result in losses to the Fund.

Money Market Risk: An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Although a money market fund generally seeks to preserve the value of its shares at $1.00 per share, there can be no assurance that it will do so, and it is possible to lose money by investing in a money market fund. A major or unexpected change in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund's share price to fall below $1.00.

U.S. Government Securities Risk: Certain U.S. government securities are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congres

sional appropriations, and their securities are not issued by the U.S. Treasury, are not supported by the full faith and credit of the U.S. government, and involve increased credit risks.

Repurchase Agreement Risk: Repurchase agreements may be viewed as loans made by the Fund, which are collateralized by the securities subject to repurchase. If the Fund's counterparty should default on its obligations and the Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Fund may realize a loss.

Stable Share Price Risk: If the market value of one or more of the Fund's investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

Market Risk: The Fund's investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors, including, but not limited to, economic growth or recession, changes in interest rates, inflation, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. Local, regional or global events such as war, military conflicts, acts of terrorism, natural disasters, the spread of infectious illness or other public health issues, or other events could have a significant impact on the Fund and its investments.

Low Short-Term Interest Rates: During market conditions in which short-term interest rates are at low levels, the Fund's yield can be very low. During these conditions, it is possible that the Fund will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Fund would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Counterparty Risk: The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

Debt Securities Risk: The values of debt securities may increase or decrease as a result of the following: market fluctuations, changes in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments, or illiquidity in debt securities markets. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. During periods when interest rates are at low levels, the Fund's yield can be low, and the Fund may have a negative yield (i.e., it may lose money on an operating basis). To the extent that interest rates fall, certain underlying obligations may be paid off substantially faster than originally anticipated. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities. High levels of inflation and/or a significantly changing interest rate environment can lead to heightened levels of volatility and reduced liquidity.

Interest Rate Risk: Interest rate risk is the risk that debt securities will decline in value because of increases in interest rates. The value of a security with a longer duration will be more sensitive to changes in interest rates than a similar security with a shorter duration. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments.

Income Risk: The Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by the Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates.

Large Shareholder Risk: To the extent a large proportion of the interests of the Portfolio are held by a small number of investors (or a single investor), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these investors will purchase or redeem Portfolio interests in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program.

Master/Feeder Structure Risk: The Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of the Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The Adviser serves as investment adviser to the master fund, leading to potential conflicts of interest. The Fund will bear its pro rata portion of the expenses incurred by the master fund. Substantial redemptions by other investors in a master fund may affect the master fund's investment program adversely and limit the ability of the master fund to achieve its objective.

Mortgage-Related and Other Asset-Backed Securities Risk: Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed-income investments. The liquidity of mortgage-related and asset-backed securities may change over time. During periods of falling interest rates, mortgage- and asset-backed securities may be called or prepaid, which may result in the Fund having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of mortgage- and asset-backed securities may extend, which may lock in a below-market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, and the underlying assets or collateral may be insufficient if the issuer defaults.

Rapid Changes in Interest Rates Risk: Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause the Fund to sell portfolio securities at a loss to satisfy those requests.

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk: To the extent the Fund focuses its investments in securities issued or guaranteed by U.S. government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. government agencies or instrumentalities in which the Fund invests may have a significant impact on the Fund's performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

U.S. Treasury Obligations Risk: U.S. Treasury obligations may differ from other fixed income securities in their interest rates, maturities, times of issuance and other characteristics. Similar to other issuers, changes to the financial condition or credit rating of the U.S. government may cause the value of the Fund's U.S. Treasury obligations to decline.

Variable and Floating Rate Securities Risk: During periods of increasing interest rates, changes in the coupon rates of variable or floating rate securities may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield.

Performance

The bar chart and table below provide some indication of the risks of investing in the U.S. Government Fund by illustrating the variability of the Fund's returns from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 1.34% (Q4, 2023)
Lowest Quarterly Return: 0.00% (Q4, 2020)

Average Annual Total Returns (for periods ended 12/31/23)

	One Year	Five Years	Since Inception	Inception Date
Institutional Class	5.04 %	1.80 %	1.79 %	1/18/2018

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

The Fund's initial and subsequent investment minimums generally are as follows, although the Fund may reduce or waive the minimums in some cases.

To establish an account	$2,000.00
To add to an existing account	$100.00

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

Send a signed letter to:
Neuberger Berman Funds
State Street Global Advisors
P.O. Box 219189
Kansas City, MO 64121-9189

By Overnight:

Send a signed letter to:
Neuberger Berman Funds
c/o State Street Institutional Trust Funds
State Street Global Advisors
430 W 7th Street Suite 219189
Kansas City, MO 64105-1407

By Telephone:

For wire transfer instructions, please call (800)-877-9700 between 9:00 a.m. and 5 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

If you wish to purchase or redeem Fund Shares through a broker, bank or other financial intermediary (“Financial Intermediary”), please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Fund is open.

Tax Information

The Fund's distributions are expected to be taxed as ordinary income unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Fund Shares through a broker-dealer or other Financial Intermediary (such as a bank), the Adviser or its affiliates may pay the Financial Intermediary for certain activities related to the Fund, including educational training programs, conferences, the development of technology platforms and reporting systems, or other services related to the sale or promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Financial Intermediary's website for more information.

State Street Institutional Treasury Plus Money Market Fund

Investment Objective

The investment objective of State Street Institutional Treasury Plus Money Market Fund (the “Treasury Plus Fund” or sometimes referred to in context as the “Fund”) is to seek a high level of current income consistent with preserving principal and liquidity and the maintenance of a stable $1.00 per share net asset value (“NAV”).

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy, hold, and sell shares of the Treasury Plus Fund (“Fund Shares”). You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street Treasury Plus Money Market Portfolio (the “Treasury Plus Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

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

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses	0.09%
Total Annual Fund Operating Expenses1	0.14%

Example:

1 year	3 years	5 years	10 years
$14	$45	$79	$179

Principal Investment Strategies

The Treasury Plus Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term securities (generally, securities that have remaining maturities of 397 calendar days or less, with the exception of certain floating rate securities that may have final maturities longer than 397 days but use maturity shortening provisions to meet the 397 day requirement, and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Treasury Plus Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Principal Risks

Performance

The bar chart and table below provide some indication of the risks of investing in the Treasury Plus Fund by illustrating the variability of the Fund's returns from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 1.33% (Q4, 2023)
Lowest Quarterly Return: 0.00% (Q3, 2021)

Average Annual Total Returns (for periods ended 12/31/23)

	One Year	Five Years	Since Inception	Inception Date
Institutional Class	5.03 %	1.80 %	1.82 %	7/30/2018

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

The Fund's initial and subsequent investment minimums generally are as follows, although the Fund may reduce or waive the minimums in some cases.

To establish an account	$2,000.00
To add to an existing account	$100.00

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

Send a signed letter to:
Neuberger Berman Funds
State Street Global Advisors
P.O. Box 219189
Kansas City, MO 64121-9189

By Overnight:

Send a signed letter to:
Neuberger Berman Funds
c/o State Street Institutional Trust Funds
State Street Global Advisors
430 W 7th Street Suite 219189
Kansas City, MO 64105-1407

By Telephone:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

The investment objective of each of the U.S. Government Fund and the Treasury Plus Fund, as stated in each Fund's Summary, may be changed without shareholder approval.

U.S. Government Fund

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund will provide shareholders with at least sixty (60) days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less, with the exception of certain floating rate securities that may have final maturities longer than 397 days but use maturity shortening provisions to meet the 397 day requirement, and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

Repurchase agreements collateralized by U.S. government securities.

Treasury Plus Fund

Principal Investment Strategies

The Treasury Plus Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

Additional Information About Risks

The Funds are subject to the following principal risks. The risks are described in alphabetical order and not in the order of importance or potential exposure. Each principal risk without a parenthetical indicating a single Fund's name is applicable to each Fund.

Counterparty Risk. A Fund will be subject to credit risk with respect to the counterparties with which a Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, a Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

Credit Risk. Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by a Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by a Fund may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when a Fund owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by a Fund loses its rating or its rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk. The values of debt securities may increase or decrease as a result of the following: market fluctuations, changes in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of a Fund's fixed income securities to decrease, an adverse impact on the liquidity of a Fund's fixed income securities, and increased volatility of the fixed income markets. During periods when interest rates are at low levels, a Fund's yield can be low, and a Fund may have a negative yield (i.e., it may lose money on an operating basis). To the extent that interest rates fall, certain underlying obligations may be paid off substantially faster than originally anticipated. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by a Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities. High levels of inflation and/or a significantly changing interest rate environment can lead to heightened levels of volatility and reduced liquidity.

Income Risk (principal risk for the U.S. Government Fund). A Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by a Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by a Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by a Fund may limit the Fund's ability to achieve its objective.

Interest Rate Risk. Interest rate risk is the risk that the securities held by a Fund will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in a Fund's income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse impact on the liquidity of a security, especially those with longer durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of a Fund's investments. High levels of inflation and/or a significantly changing interest rate environment can lead to heightened levels of volatility and reduced liquidity.

Large Shareholder Risk. To the extent a large proportion of the interests of a Portfolio are highly concentrated or held by a small number of investors (or a single investor), including funds or accounts over which the Adviser has investment discretion, a Portfolio is subject to the risk that these investors will purchase or redeem Portfolio interests in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of a Portfolio to conduct its investment program. For example, they could require a Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to investors, or a Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case a Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. A Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Low Short-Term Interest Rate Risk. During market conditions in which short-term interest rates are at low levels, a Fund's yield can be very low. During these conditions, it is possible that a Fund will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that a Fund would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Market Disruption and Geopolitical Risk. A Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters, pandemics and epidemics, and systemic market dislocations may be highly disruptive to economies and markets. Those events, as well as other changes in foreign and domestic economic and political conditions, also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of a Fund's investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Fund's investments. On January 31, 2020, the United Kingdom (“UK”) formally withdrew from the European Union (“EU”) (commonly known as “Brexit”). An agreement between the UK and the EU governing their future trade relationship became effective January 1, 2021, but critical aspects of the relationship remain unresolved and subject to further negotiation and agreement. There is still considerable uncertainty relating to the potential consequences associated with the exit, how the negotiations for new trade agreements will be conducted, and whether the UK's exit will increase the likelihood of other countries also departing the EU. Brexit may have a significant impact on the UK, Europe, and global economies, which may result in increased volatility and illiquidity, new legal, political, economic and

regulatory uncertainties and potentially lower economic growth for these economies that could potentially have an adverse effect on the value of the Funds' investments. Any further exits from the EU, or the possibility of such exits, or the abandonment of the euro, may cause additional market disruption globally and introduce new legal and regulatory uncertainties.

Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by a Fund. To the extent a Fund has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Fund.

Market Risk. Market prices of investments held by a Fund will go up or down, sometimes rapidly or unpredictably. A Fund's investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile, and prices of investments can change substantially due to various factors, including, but not limited to, economic growth or recession, changes in interest rates, inflation, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in a Fund could decline if the particular industries, sectors or companies in which the Fund invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices. Local, regional or global events such as war, military conflicts, acts of terrorism, natural disasters, public health issues, or other events could have a significant impact on a Fund and its investments. Due to the interconnectedness of economies and financial markets throughout the world, if a Fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the Fund's investments may be negatively affected. A widespread outbreak of an infectious illness, such as COVID-19, and efforts to contain its spread, may result in market volatility, inflation, reduced liquidity of certain instruments, disruption in the trading of certain instruments, and systemic economic weakness. The foregoing could impact a Fund and its investments and result in disruptions to the services provided to a Fund by its service providers.

Additionally, in the Spring of 2023, the shutdown of certain financial institutions raised economic concerns over disruption in the U.S. banking system. There can be no certainty that the actions taken by the U.S. government to strengthen public confidence in the U.S. banking system will be effective in mitigating the effects of financial institution failures on the economy and restoring public confidence in the U.S. banking system.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject a Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and a Fund's investment program in particular can be uncertain. Governmental and non-governmental issuers may default on, or be forced to restructure, their debts, and other issuers may face difficulties obtaining credit. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Master/Feeder Structure Risk. Each Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of a Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The ability of a Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the master fund. The ability of a Fund to meet redemption requests will depend on its ability to redeem its interest in the master fund. The Adviser or an affiliate serves as investment adviser to the master fund, leading to potential conflicts of interest. For example, the Adviser or its affiliates will receive fees based on the amount of assets invested in the master fund. Investment by a Fund in the master fund may be beneficial in the management of the master fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by a Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the

Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so. A Fund will bear its pro rata portion of the expenses incurred by the master fund.

Money Market Fund Regulatory Risk. Money market funds and the securities they invest in are subject to comprehensive regulations. The SEC has adopted amendments to money market fund regulation that, among other things, increase the daily and weekly liquid asset requirements (“Money Market Fund Reform”). Money Market Fund Reform permits government money market funds (such as the Funds), that are experiencing a negative gross yield as a result of negative interest rates, to either convert from a stable share price to a floating share price or reduce the number of shares outstanding (e.g., through a reverse stock split) to maintain a stable net asset value per share, subject to certain Board determinations and disclosures to investors. A Fund's operations will be impacted as it comes into compliance with the Money Market Fund Reform. The SEC and other government agencies continue to review the regulation of money market funds and may implement additional regulatory changes in the future. The enactment of any new legislation or regulations impacting the money market fund industry could limit the Fund's investment flexibility and reduce its ability to generate returns.

Money Market Risk. An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Although a money market fund generally seeks to preserve the value of its shares at $1.00 per share, there can be no assurance that it will do so, and it is possible to lose money by investing in a money market fund. A major or unexpected change in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund's share price to fall below $1.00. It is possible that a money market fund will issue and redeem shares at $1.00 per share at times when the fair value of the money market fund's portfolio per share is more or less than $1.00. Rule 2a-7 as adopted by the SEC permits a money market fund to impose a liquidity fee upon the sale of fund shares under certain circumstances, however the Treasury Plus Fund and U.S. Government Fund are both government money market funds that have not elected to be subject to the liquidity fee provision of Rule 2a-7. None of State Street Corporation, State Street, State Street Global Advisors, SSGA FM or their affiliates (collectively, the “State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from the State Street Entities.

Mortgage-Related and Other Asset-Backed Securities Risk (principal risk for the U.S. Government Fund). Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in a Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which a Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools,

and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Rapid Changes in Interest Rates. The values of instruments held by a Fund may be adversely affected by rapid changes in interest rates. Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause a Fund to sell portfolio securities at a loss to satisfy those requests. Significant losses could impair a Fund's ability to maintain a stable share price of $1.00.

Reinvestment Risk (principal risk for the U.S. Government Fund). Income from a Fund's portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing a Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by a Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Repurchase Agreement Risk. A repurchase agreement is an agreement to buy a security from a seller at one price and a simultaneous agreement to sell it back to the original seller at an agreed-upon price, typically representing the purchase price plus interest. Repurchase agreements may be viewed as loans made by a Fund, which are collateralized by the securities subject to repurchase. A Fund's investment return on such transactions will depend on the counterparty's willingness and ability to perform its obligations under a repurchase agreement. If a Fund's counterparty should default on its obligations and a Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, a Fund may realize a loss.

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk (principal risk for the U.S. Government Fund). To the extent a Fund focuses its investments in securities issued or guaranteed by U.S. government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. government agencies or instrumentalities in which the Fund invests may have a significant impact on a Fund's performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Stable Share Price Risk. If the market value of one or more of the Fund's investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

U.S. Government Securities Risk (principal risk for the U.S. Government Fund). U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least two major rating agencies has introduced greater uncertainty about the ability of the U.S. to repay its obligations. Further credit rating downgrades or a U.S. credit default could decrease the value and increase the volatility of a Fund's investments.

U.S. Treasury Obligations Risk. U.S. Treasury obligations may differ from other securities in their interest rates, maturities, times of issuance and other characteristics. Similar to other issuers, changes to the financial condition or credit rating of the U.S. government may cause the value of a Fund's U.S. Treasury obligations to decline. The total public debt of the United States as a percent of gross domestic product grew rapidly after the financial crisis of 2008 and has remained at a historically high level. Although high debt levels do not necessarily indicate or cause economic problems, they may create certain systemic risks if sound debt management practices are not implemented. A high national debt level may increase market pressures to meet government funding needs, which may drive debt cost higher and cause a country to sell additional debt, thereby increasing refinancing risk. A high national debt also raises concerns that a government will not be able to make principal or interest payments when they are due. In the worst case, unsustainable debt levels can cause a decline in the value of the dollar (which may lead to inflation), and can prevent the U.S. government from implementing effective countercyclical fiscal policy in economic downturns. On August 5, 2011, Standard & Poor's Ratings Services downgraded U.S. Treasury securities from AAA rating to AA+ rating. Standard & Poor's Ratings Services stated that its decision was prompted by its view on the rising public debt burden and its perception of greater policymaking uncertainty. Fitch downgraded its rating of U.S. Treasury securities in August 2023. A downgrade of the ratings of U.S. government debt obligations, which are often used as a benchmark for other borrowing arrangements, could result in higher interest rates for individual and corporate borrowers, cause disruptions in the international bond markets and have a substantial negative effect on the U.S. economy. Any additional downgrades of U.S. Treasury securities from ratings agencies may cause the value of the Fund's U.S. Treasury obligations to decline. In recent years, impasses in Congress regarding the federal budget have caused repeated temporary Federal government shutdowns. While Congress has temporarily suspended the debt limit from time to time, the risks that the U.S. government will not adopt a long-term budget or deficit reduction plan, of one or more additional Federal government shutdowns or of future failures to not increase the Federal government's debt limit, may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree.

Variable and Floating Rate Securities Risk. Variable or floating rate securities are debt securities with variable or floating interest rates payments. Variable or floating rate securities bear rates of interest that are adjusted periodically according to formulae intended generally to reflect market rates of interest and allow a Fund to participate (determined in accordance with the terms of the securities) in increases in interest rates through upward adjustments of the coupon rates on the securities. However, during periods of increasing interest rates, changes in the coupon rates may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. A Fund may also invest in variable or floating rate equity securities, whose dividend payments vary based on changes in market rates of interest or other factors.

Additional Information About Non-Principal Investment Strategies and Risks

The investments described below reflect the Funds' and the Portfolios' current practices. In addition to the principal risks described above, other risks are described in some of the descriptions of the investments below:

Conflicts of Interest Risk. An investment in a Fund will be subject to a number of actual or potential conflicts of interest. For example, the Adviser or its affiliates may provide services to a Fund, such as securities lending agency services, custodial, administrative, bookkeeping, and accounting services, transfer agency and shareholder servicing, securities brokerage services, and other services for which the Fund would compensate the Adviser and/or such affiliates. The Funds may invest in other pooled investment vehicles sponsored, managed, or otherwise affiliated with the Adviser. There is no assurance that the rates at which a Fund pays fees or expenses to the Adviser or its affiliates, or the terms on which it enters into transactions with the Adviser or its affiliates will be the most favorable available in the market generally or as favorable as the rates the Adviser or its affiliates make available to other clients. Because of its financial interest, the Adviser will have an incentive to enter into transactions or arrangements on behalf of a Fund with itself or its affiliates in circumstances where it might not have done so in the absence of that interest, provided that the Adviser will comply with applicable regulatory requirements.

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Funds. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for a Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other

clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by a Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Funds) or otherwise using such information for the benefit of its clients or itself.

The foregoing does not purport to be a comprehensive list or complete explanation of all potential conflicts of interests which may affect a Fund. A Fund may encounter circumstances, or enter into transactions, in which conflicts of interest that are not listed or discussed above may arise.

Cybersecurity Risk. With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In addition, the global spread of COVID-19 caused the Funds, the Portfolios and their service providers to implement business continuity plans, including widespread use of work-from-home arrangements. Furthermore, geopolitical tensions may have increased the scale and sophistication of deliberate cybersecurity attacks, particularly those from nation-states or from entities with nation-state backing. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, a Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified, given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invests, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

Risk of Investment in Other Pools. If a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the

sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Temporary Defensive Positions. In response to actual or perceived adverse market, economic, political, or other conditions, a Fund may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. While investing defensively, the Fund may maintain a substantial portion of its assets in cash, on which the Fund may earn little if any income. If a Fund invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

Portfolio Holdings Disclosure

The portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

Management and Organization

Each Fund is a separate, diversified series of the State Street Institutional Investment Trust (the “Trust”), which is an open-end management investment company organized as a business trust under the laws of the Commonwealth of Massachusetts.

Each Fund invests as part of a “master/feeder” structure. Each Fund currently seeks to achieve its investment objective by investing substantially all of its investable assets in a corresponding Portfolio, a separate mutual fund, that has substantially identical investment objective, investment policies, and risks as the Fund. All discussions about a Fund's investment objective, policies and risks should be understood to refer also to the investment objectives, policies and risks of the corresponding Portfolio.

A Fund can withdraw its investment in a Portfolio if, at any time, the Fund's Board of Trustees (the “Board” and each member thereof, a “Trustee”) determines that it would be in the best interests of the Fund's shareholders, or if the investment objectives of the corresponding Portfolio changed so that they were inconsistent with the objectives of the Fund. If a Fund withdraws its investment from a Portfolio, the Fund may invest all of its assets in another mutual fund that has the same investment objective as the Fund, the Adviser may directly manage the Fund's assets, or the Board may take such other action it deems appropriate and in the best interests of shareholders of the Fund, which may include liquidation of the Fund.

Investment Adviser

SSGA FM serves as the investment adviser to each Fund and corresponding Portfolio and, subject to the oversight of the Board, is responsible for the investment management of each Fund. The Adviser provides an investment management program for each Fund and manages the investment of each Fund's assets. In addition, the Adviser provides administrative, compliance and general management services to each Fund. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the SEC under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2023, the Adviser managed approximately $955.79 billion in assets and SSGA managed approximately $4.13 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

Each Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund's assets directly, for compensation paid at an annual rate of 0.05% of the Fund's average daily net assets, in the event that the Fund were to cease investing substantially all of its assets in its corresponding Portfolio or another investment company with essentially the same investment objectives and policies as the Fund. The Adviser does not receive any management fees from a Fund under that agreement so long as the Fund continues to invest substantially all of its assets in the corresponding Portfolio or in another investment company with essentially the same investment objectives and policies as the Fund. The Adviser places all orders for purchases and sales of the Portfolios' investments. For the year ended December 31, 2023, the effective management fee paid, reflecting certain fee waivers and expense reimbursements of the Adviser, was 0.05% for Treasury Plus Portfolio and 0.05% for U.S. Government Portfolio.

Total Annual Fund Operating Expense Waivers. SSGA FM, as the investment adviser to each Fund is contractually obligated, through April 30, 2025 (i) to waive up to the full amount of the advisory fee payable by each Fund, and/or (ii) to reimburse a Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.07% of average daily net assets on an annual basis (the “Total Annual Fund Operating Expense Waiver”). The Total Annual Fund Operating Expense Waiver may not be terminated prior to April 30, 2025 with respect to any Fund except with approval of the Fund's Board of Trustees.

In addition to any contractual expense limitation for a Fund, which is described above, each of the Adviser and State Street Global Advisors Funds Distributors, LLC (each a “Service Provider”) also may voluntarily reduce all or a portion of its fees and/or reimburse expenses for a Fund or a share class to the extent necessary to maintain a certain minimum net yield, which may vary from time to time and from share class to share class within a Fund, in SSGA FM's sole discretion (any such waiver or reimbursement of expenses being referred to herein as a “Voluntary Reduction”). Under an

agreement with the Service Providers relating to the Voluntary Reduction, the Funds and the Portfolios have agreed to reimburse the Service Providers for the full dollar amount of any Voluntary Reduction beginning on May 1, 2020, subject to certain limitations. Each Service Provider may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from a Fund.

A reimbursement to the Service Provider would increase fund expenses and may negatively impact a Fund's yield during such period. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that a Fund will be able to avoid a negative yield. The Funds have agreed, subject to certain limitations, to reimburse the applicable Service Provider for the full dollar amount of any Voluntary Reduction incurred after May 1, 2020. A Fund is not obligated to reimburse a Service Provider: (1) more than three years after the end of the fiscal year of the Fund in which the Service Provider provided a Voluntary Reduction; (2) in respect of any business day for which the net annualized oneday yield of the Fund or applicable Class is less than 0.00%; (3) to the extent that the amount of the reimbursement to all Service Providers on any day exceeds fifty percent of the yield (net of all expenses, exclusive of the reimbursement) of the Fund or the applicable class on that day; (4) to the extent that the amount of such reimbursement would cause the Fund's or applicable class's net yield to fall below the Fund's or applicable class's minimum yield; (5) in respect of any such fee waivers and/or expense reimbursements that are necessary to maintain the Fund's Contractual Total Expense Limit (as defined in the Reimbursement Agreement) which is effective at the time of such fee waivers and/or expense reimbursements; or (6) in any manner that would result in a class bearing the cost of a reimbursement to the Service Provider for any class-specific expense (including, without limitation, fees payable in accordance with a plan authorized pursuant to Rule 12b-1 under the 1940 Act, or Shareholder Servicing Agreement or similar arrangement) that was waived or reimbursed to the Fund with respect to a different Class. Any such future reimbursement of an applicable Service Provider may result in the total annual operating expenses with respect to a share class of a Fund exceeding the amount of the expense cap under the contractual expense limitation agreement because the expense is not covered by the agreement.

A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Funds' Semi-Annual Report to Shareholders for the period ended June 30, 2023.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of each Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. Each Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Funds for a fee that is paid by the Adviser. State Street also serves as custodian of the Funds for a separate fee that is paid by the Funds. SSGA FM serves as administrator of the Portfolios and State Street serves as sub-administrator and custodian of the Portfolios.

The Transfer Agent and Dividend Disbursing Agent

SS&C GIDS, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

The Shareholder Servicing Agent

SSGA FD serves as the Funds' shareholder servicing agent pursuant to the Shareholder Servicing Agreement between SSGA FD and the Trust and receives fees from the Funds for the provision and procurement of applicable services. Please see the SAI for more information on SSGA FD's role as the Funds' shareholder servicing agent.

The “Servicing Agent”

Neuberger Berman Investment Advisers LLC (“Neuberger Berman”) serves as the servicing agent for shareholders of mutual funds distributed and advised by Neuberger Berman (a “Neuberger Berman Fund”) that are also shareholders of a Fund.

Additional Information

The Trustees of the Trust oversee generally the operations of the Funds and the Trust. The Trust enters into contractual arrangements with various parties, including, among others, the Funds' investment adviser, custodian, transfer agent, and accountants, who provide services to the Funds. Shareholders are not parties to any such contractual arrangements or intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them directly against the service providers or to seek any remedy under them directly against the service providers.

This Prospectus provides information concerning the Trust and the Funds that you should consider in determining whether to purchase shares of the Funds. Neither this Prospectus, nor the related SAI, is intended, or should be read, to be or to give rise to an agreement or contract between the Trust or the Funds and any investor, or to give rise to any rights in any shareholder or other person other than any rights under federal or state law that may not be waived.

Shareholder Information

Note: This prospectus is intended to relate principally to purchases of shares through Neuberger Berman. Information appearing below assumes that shares are purchased and redeemed through Neuberger Berman and is based on information previously provided by Neuberger Berman to the Funds.

Determination of Net Asset Value

Each of the Funds determines its NAV per share once each day on which the New York Stock Exchange (the “NYSE”), the Federal Reserve banks and State Street are open for business (a “Business Day”) at 5:00 p.m. ET except for days when the NYSE closes earlier than its regular closing time, in which event the Fund will determine its NAV at the earlier closing time (the time when the Fund determines its NAV per share is referred to herein as the “Valuation Time”). Pricing does not occur on NYSE holidays.

The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Funds reserve the right to accept orders to purchase or redeem shares, or to continue to accept such orders following the close of the NYSE, on any day that is not a Business Day or any day on which the NYSE closes early, provided the Federal Reserve remains open. The Funds also may establish special hours on those days to determine each Fund's NAV. In the event that the Funds invoke the right to accept orders to purchase or redeem shares on any day that is not a Business Day or adopt special hours of operation, the Funds will post advance notice of these events at: www.ssga.com/cash.

Each Fund seeks to maintain a $1.00 per share NAV and, accordingly, uses the amortized cost valuation method, in compliance with the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

If you hold shares of a Fund through a broker-dealer or other financial intermediary, your intermediary may offer additional services and account features that are not described in this Prospectus. Please contact your intermediary directly for an explanation of these services.

Investing in State Street Institutional Investment Trust Shares

Mutual funds advised by SSGA FM (the “State Street Funds”) and their service providers have a legal obligation to collect from you certain personal information about you at the time you open an account in order to verify your identity and the source of your payment. If you do not provide this information, you may not be able to open an account with the State Street Funds. If the State Street Funds believe that they have uncovered unlawful activity, the State Street Funds and their service providers may close your account and take any action they deem reasonable or required by law. The State Street Funds reserve the right to reject any purchase order.

Requests for transactions in the State Street Funds will be processed when they are received in “good order.” “Good order” means that the request is in an accurate and complete form, and all applicable documents have been received in such accurate and complete form (including, typically, a signed application and medallion-guaranteed documents), and, for a purchase request, the check or wired funds have cleared.

Purchasing Shares

Investors pay no sales load to invest in shares of the Funds. The price for Fund Shares is the NAV per share. Purchase requests received by a Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of

a completed and signed application and all documentation necessary to open an account) on a Business Day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Time will earn dividend accrual for that purchase.

All purchases that are made by check will begin earning dividends the following Business Day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Funds. The Funds intend to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Funds' custodian bank by a Federal Reserve Bank).

Neuberger Berman is responsible for transmitting your purchase request and funds in good form and in a timely manner to the applicable Fund(s). A Fund will not be responsible for delays by Neuberger Berman in transmitting your purchase request, including timely transfer of payment, to the Fund.

The Funds reserve the right to cease accepting investments at any time or to reject any investment order. In addition, the Funds may limit the amount of a purchase order received after 3:00 p.m. ET.

How to Purchase Shares

By Mail:

An initial investment in the Funds must be preceded or accompanied by a completed, signed Neuberger

Berman Fund Application Form, sent to:

Neuberger Berman Funds

c/o State Street Institutional Trust Funds

State Street Global Advisors

430 W 7th Street Suite 219189

Kansas City, MO 64105-1407

Your first investment must be at least $2,000. Additional investments can be as little as $100. All checks must be

made out to “Neuberger Berman Funds”. Neuberger Berman will not accept checks made out to you or other

parties and signed over to it. Neuberger Berman cannot accept cash, money orders, starter checks, cashier's

checks, traveler's checks or other cash equivalents. You will be responsible for any losses or fees resulting from a

bad check. If necessary, Neuberger Berman may effect sales of Fund shares belonging to you in order to cover

these losses.

By Telephone:

An initial investment in the Funds must be preceded or accompanied by a completed, signed Neuberger

Berman Fund Application Form. Neuberger Berman does not accept phone orders for a first investment. To add

shares to an existing account using FUNDfone®», call (800) 335-9366.

Additional shares will be purchased when your order is accepted by the Funds. Additional investments must be

for at least $100.

For your initial investment, send the original, signed Neuberger Berman Account Application Form to the address

above.

Wire Instructions:

Before wiring any money, call (800) 877-9700 for an order confirmation. Please have your financial institution

send your wire to Neuberger Berman's account at State Street Bank and Trust Company and include your name,

the Fund name, your account number and other information as requested.

State Street Bank/Boston

ABA# 011-000028

Attn: NB Deposit Account

DDA#9904-199-8

On Columbus Day and Veterans Day, you will not be able to purchase shares by wiring Federal Funds because the

Federal Funds wiring does not occur on those days. Payment for Fund Shares must be in Federal Funds (or

converted to Federal Funds by the Transfer Agent) by the close of the Federal Reserve.

By Internet:

You may place an order with Neuberger Berman to purchase shares for your account by placing an order

online at www.nb.com.

You will not be able to redeem shares from the account until the original Application has been

received. The Funds and the Funds' agents are not responsible for transfer errors by the sending or receiving bank

and will not be liable for any loss incurred due to a wire transfer not having been received.

In accordance with certain federal regulations, Neuberger Berman is required to obtain, verify and record information that identifies each entity that applies to open an account. For this reason, when you open (or change ownership of) an account, Neuberger Berman will request certain information, including your name, residential/business address, date of birth (for individuals) and taxpayer identification number or other government identification number and other information that will allow us to identify you which will be used to verify your identity. Neuberger Berman may also request to review other identification documents such as driver license, passport or documents showing the existence of the business entity. If you do not provide sufficient information to verify your identity, Neuberger Berman will not open an account for you. As required by law, Neuberger Berman may employ various procedures, such as comparing your information to fraud databases or requesting additional information and documentation from you, to ensure that the information supplied by you is correct. Neuberger Berman reserves the right to reject any purchase for any reason, including failure to provide the Trust with information necessary to confirm your identity as required by law.

Redeeming Shares

An investor may redeem all or any portion of its investment. Redemption orders are processed at the NAV next determined after a Fund receives a redemption order in good form to Neuberger Berman.

For the Treasury Plus Fund

If Neuberger Berman receives a redemption order in good form prior to 4:30 p.m. Eastern Time on a Business Day, shares are redeemed and Neuberger Berman typically expects to pay out redemption proceeds on that day, but no later than the next Business Day, if redemption proceeds are sent by wire or ACH. No dividends will be paid on shares that are redeemed and wired the same day. If redemption proceeds are sent by check, Neuberger Berman typically expects to pay out redemption proceeds on the next Business Day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after 4:30 p.m. Eastern Time, Neuberger Berman typically expects to pay out the redemption proceeds for the shareholder the next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). The Treasury Plus Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

For the U.S. Government Fund

If Neuberger Berman receives a redemption order in good form prior to 4:30 p.m. Eastern Time on a Business Day, shares are redeemed and Neuberger Berman typically expects to pay out redemption proceeds on that day, but no later than the next Business Day, if redemption proceeds are sent by wire or ACH. No dividends will be paid on shares that are redeemed and wired the same day. If redemption proceeds are sent by check, Neuberger Berman typically expects to pay out redemption proceeds on the next Business Day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after 4:30 p.m. Eastern Time, Neuberger Berman typically expects to pay out the redemption proceeds for the shareholder the next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). The U.S. Government Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

For All Funds

Rule 2a-7 as adopted by the SEC permits a money market fund to impose a liquidity fee upon the sale of fund shares under certain circumstances, however the U.S. Government Fund and the Treasury Plus Fund are both government money market funds that have not elected to be subject to the liquidity fee provision of Rule 2a-7. The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed in accordance with Section 22(e) of the 1940 Act and the rules thereunder, including during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or if an emergency exists as a result of which disposal by the Fund of securities owned by it is not reasonably practicable or it is not reasonably practicable for the Fund fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Fund. Although each Fund attempts to maintain its NAV at $1.00 per share, there can be no assurance that it will be successful, and there can be no assurance that a shareholder will receive $1.00 per share upon any redemption.

When selling shares in an account that you do not intend to close, remember to leave at least $2,000 worth of shares in the account. Otherwise, Neuberger Berman has the right to request that you bring the balance back up to the minimum level. If you have not done so within 60 days, Neuberger Berman may close your account and redeem the proceeds. Neuberger Berman is responsible for transmitting your redemption request in good form and in a timely manner to the applicable Fund(s). A Fund will not be responsible for delays by Neuberger Berman in transmitting your redemption request to the Fund.

The transfer agent may temporarily delay for more than seven days the disbursement of redemption proceeds from the Fund account of a “Specified Adult” (as defined in Financial Industry Regulatory Authority, Inc. (“FINRA”) Rule 2165) based on a reasonable belief that financial exploitation of the Specified Adult has occurred, is occurring, has been attempted, or will be attempted, subject to certain conditions.

How to Redeem Shares


By Mail:	Send a signed letter to: Neuberger Berman Funds c/o State Street Bank & Trust Co. 430 West 7th Street Suite 219189 Kansas City, MO 64105-1407
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Telephone:	Please call Neuberger Berman at (800) 877-9700 between the hours of 9:00 a.m. and 5:00 p.m. ET.
You must provide the following information: ➢ name(s) of account owners; ➢ account number(s); ➢ the name of the Fund; ➢ the dollar amount, percentage or number of shares being redeemed; and ➢ any other instructions. To place an order using FUNDfone®», call (800) 335-9366.
By Internet:	You may instruct Neuberger Berman to redeem shares by placing an order online at www.nb.com.

On any day that the Funds calculate NAV earlier than normal, the Funds reserve the right to adjust the times noted above for purchasing and redeeming shares.

Medallion Guarantees. You may need a Medallion signature guarantee when you sell shares of a Fund. A Medallion signature guarantee is a guarantee that your signature is authentic. Most banks, brokers and other financial institutions can provide you with one. Some may charge a fee; others may not, particularly if you are a customer of theirs.

Medallion signature guarantees are required for a variety of transactions including requests for changes to your account or to the instructions for distribution of proceeds. Neuberger Berman reserves the right to require a Medallion signature guarantee on any transaction at our discretion.

A notarized signature from a notary public is not a Medallion signature guarantee.

Exchanging Shares. You can move an investment from a Fund to a comparable class of another Neuberger Berman Fund in the Fund family through an exchange of shares, or by electing to use your cash distributions from a Fund to purchase shares of the other Fund. There are three things to remember when making an exchange:

•

both accounts must have the same registration;

•

you will need to observe the minimum account balance requirements for the fund accounts involved; and

•

because an exchange is treated as a sale for tax purposes, consider any tax consequences before placing your order.

Privileges and Services. You have access to a range of Neuberger Berman services to make investing easier:

Systematic Withdrawals. This plan lets you arrange withdrawals of at least $100 from a Fund on a periodic schedule. You can also set up payments to distribute the full value of an account over a given time.

Electronic Bank Transfers. When you sell Fund shares, you can have the money sent to your bank account electronically rather than mailed to you as a check. Please note that your bank must be a member of the Automated Clearing House, or ACH, system.

Internet Access. At www.nb.com, you can initiate transactions, check your account and access a wealth of information.

FUNDfone®. Get up-to-date performance and account information through our 24-hour automated service by calling (800) 335-9366. If you already have a Neuberger Berman fund account, you can place orders to buy, sell or exchange fund shares.

Checkwriting. If you would like to write checks against your Institutional U.S. Government Money Market Fund account, please call (800) 877-9700. Withdrawals must be for at least $250.

About Mail Transactions. If you choose to purchase, exchange or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 West 7th Street, Suite 219189 in Kansas City, MO 64105. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and a Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Other Policies. Under certain circumstances, Neuberger Berman reserves the right to:

•

reject any exchange or purchase order;

•

suspend or reject any future purchase order from any investor who does not provide payment to settle a purchase order;

•

change, suspend or revoke the exchange privilege; and

•

suspend the telephone order privilege.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

It is your responsibility to ensure that you maintain a correct address for your account, and maintain contact in ways such as by contacting the Funds' transfer agent by mail or telephone or accessing your account through the Funds' website, and promptly cashing all checks for dividends, capital gains and redemptions. State requirements for maintaining contact with an account can vary and are subject to change. If you invest in a Fund through a financial intermediary, we encourage you to contact the financial intermediary regarding applicable state unclaimed property laws. The Funds, the transfer agent and the distributor will not be liable to shareholders or their representatives for good faith compliance with state unclaimed property laws. Please check your state's unclaimed or abandoned property website for specific information.

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Excessive Trading

Because the Funds are money market funds, the Board has not adopted policies and procedures with respect to frequent purchases and redemptions of Fund shares by Fund shareholders. Nonetheless, the Funds may take any reasonable action that they deem necessary or appropriate to prevent excessive trading in Fund shares without providing prior notification to the account holder. Such action may include rejecting any purchase, in whole or part, including, without limitation, by a person whose trading activity in Fund shares may be deemed harmful to the Fund. While the Funds

attempt to discourage such excessive trading, there can be no guarantee that they will be able to identify investors who are engaging in excessive trading or limit their trading practices. Additionally, frequent trades of small amounts may not be detected. The Funds recognize that they may not always be able to detect or prevent excessive trading or other activity that may disadvantage the Funds or their shareholders.

Dividends, Distributions and Tax Considerations

The Funds intend to declare dividends on shares from net investment income daily and pay them as of the last Business Day of each month. Distributions from capital gains, if any, will be made annually in December. Dividends of investment income and capital gain distributions will be paid in additional shares on the reinvestment date unless you have elected to receive them in cash. No interest will accrue on the amounts represented by uncashed distribution checks. If you have elected to receive distributions by check, and the postal or other delivery service is unable to deliver the checks because of an incorrect mailing address, or if a distribution check remains uncashed for six months, the uncashed distribution and all future distributions will be reinvested at the then-current NAV of the Fund.

The following discussion is a summary of some important U.S. federal income tax considerations generally applicable to an investment in a Fund. Your investment in a Fund may have other tax implications. Please consult your tax advisor about federal, state, local, foreign or other tax laws applicable to you. Investors, including non-U.S. investors, may wish to consult the SAI tax section for additional disclosure.

Each Fund has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, a Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. A Fund's failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

Each Fund invests substantially all of its investable assets in a corresponding Portfolio that is treated as a partnership for U.S. federal income tax purposes. Therefore, the nature and character of each Fund's income, gains, losses and deductions generally will be determined at the Portfolio level, and each Fund will be allocated its share of the corresponding Portfolio's income, gains, losses and deductions. As applicable, references in this discussion to income, gains and losses of a Fund will be to income, gains and losses recognized and deductions accruing at the Portfolio level and allocated to or otherwise taken into account by the Fund, and references to assets of a Fund will be to the Fund's allocable share of the assets of the corresponding Portfolio.

For U.S. federal income tax purposes, distributions of investment income are generally taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Portfolio or Fund owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Any net short-term gains the Fund distributes will be taxable to you as ordinary income. The Funds generally do not expect to make distributions that are eligible for taxation as long-term capital gains. Distributions are taxable to you even if they are paid from income or gains earned by a Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares. Distributions in excess of a Fund's current and accumulated earnings and profits are treated as a return of capital to the extent of your basis in the applicable Fund's shares, and, in general, as capital gain thereafter.

If the NAV of Fund Shares were to vary from $1.0000 per share, shareholders generally would realize a gain or loss upon the redemption or other taxable disposition of such Fund Shares. Any such gains generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you have held such Fund Shares. The Internal Revenue Service (the “IRS”) has issued final regulations and published guidance that permit a simplified method of accounting for gains and losses realized upon the disposition of money market fund shares. Shareholders should see the SAI for further information.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by a Fund and net gains recognized on the redemption (or other taxable disposition) of Fund Shares.

If you are not a U.S. person, dividends paid by a Fund that the Fund properly reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends, each as further defined in the SAI, are not subject to withholding of U.S. federal income tax, provided that certain requirements are met. A Fund is permitted, but is not required, to report any part of its dividends as are eligible for such treatment. A Fund's dividends other than those the Fund so reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends generally will be subject to U.S. withholding tax at a 30% rate (or lower applicable treaty rate). See each Fund's SAI for further information.

The U.S. Treasury and IRS generally require a Fund to obtain information sufficient to identify the status of each shareholder under sections 1471-1474 of the Internal Revenue Code of 1986, as amended, and the U.S. Treasury and IRS guidance issued thereunder (collectively, “FATCA”) or under an applicable intergovernmental agreement between the United States and a foreign government. Please see the SAI for more information on FATCA reporting requirements.

Financial Intermediary Arrangements

Payments to Financial Intermediaries

Financial Intermediaries are firms that sell shares of mutual funds, including the Funds, and/or provide certain administrative and account maintenance services to mutual fund investors. Financial Intermediaries may include, among others, brokers, financial planners or advisers, banks, retirement plan recordkeepers and insurance companies.

In some cases, a Financial Intermediary may hold its clients' Fund Shares in nominee or street name and may utilize omnibus accounts. Shareholder services provided by a Financial Intermediary may (though they will not necessarily) include, among other things: establishing and maintaining shareholder account registrations; receiving and processing purchase and redemption orders, including aggregated orders and delivering orders to the Fund's transfer agent; processing and mailing trade confirmations, periodic statements, prospectuses, annual reports, semiannual reports, shareholder notices, and other SEC-required communications; capturing and processing tax data; issuing and mailing dividend checks to shareholders who have selected cash distributions; preparing record date shareholder lists for proxy solicitations; and collecting and posting distributions to shareholder accounts.

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Funds. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Funds or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Funds or its affiliates with respect to the different share classes offered by the Funds.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

If payments to Financial Intermediaries by the distributor or adviser for a particular mutual fund complex exceed payments by other mutual fund complexes, your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend that fund complex over others. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by SSGA FD and its affiliates and by sponsors of other mutual funds he or she may recommend to you. You should also consult disclosures made by your Financial Intermediary at the time of purchase.

Financial Highlights

The financial highlight tables are intended to help you understand each Fund's Institutional Class Shares financial performance since inception of Institutional Class shares. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in each Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with each Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of each Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Institutional Class (a)
	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
Net asset value, beginning of period	$1.0000	$1.0000	$1.0000	$1.0000	$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0491	0.0156	0.0001	0.0037	0.0207
Net realized gain (loss)	0.0000 (b)	0.0000 (b)	—	0.0000 (b)	0.0000 (b)
Total from investment operations	0.0491	0.0156	0.0001	0.0037	0.0207
Distributions to shareholders from:
Net investment income	(0.0491 )	(0.0156 )	(0.0001 )	(0.0037 )	(0.0207 )
Net asset value, end of period	$1.0000	$1.0000	$1.0000	$1.0000	$1.0000
Total return (c)	5.04 %	1.58 %	0.03 %	0.37 %	2.09 %
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$10,784,799	$3,373,375	$1,588,396	$1,349,398	$950,202
Ratios to Average Net Assets:
Total expenses	0.15 %	0.15 %	0.15 %	0.15 %	0.15 %
Net expenses	0.15 %	0.14 %	0.04 %	0.14 %	0.15 %
Net investment income (loss)	5.08 %	2.06 %	0.03 %	0.42 %	1.95 %

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods of less than one year are not annualized. Results represent past performance and are not indicative of future results.

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Institutional Class (a)
	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
Net asset value, beginning of period	$1.0000	$1.0000	$1.0000	$1.0000	$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0492	0.0157	0.0001	0.0037	0.0207
Net realized gain (loss)	0.0000 (b)	—	—	—	0.0000 (b)
Total from investment operations	0.0492	0.0157	0.0001	0.0037	0.0207
Distributions to shareholders from:
Net investment income	(0.0492 )	(0.0157 )	(0.0001 )	(0.0037 )	(0.0207 )
Net asset value, end of period	$1.0000	$1.0000	$1.0000	$1.0000	$1.0000
Total return (c)	5.03 %	1.58 %	0.02 %	0.37 %	2.09 %
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$3,278,847	$2,122,508	$278,027	$90,569	$468,721
Ratios to Average Net Assets:
Total expenses	0.14 %	0.15 %	0.15 %	0.15 %	0.15 %
Net expenses	0.14 %	0.15 %	0.06 %	0.15 %	0.15 %
Net investment income (loss)	5.00 %	2.57 %	0.02 %	0.34 %	2.09 %

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods of less than one year are not annualized. Results represent past performance and are not indicative of future results.

For more information about the Funds:

The SAI includes additional information about the Funds and is incorporated by reference into this document. Additional information about the investments is available in the most recent annual and semi-annual reports to shareholders. The SAI is available, without charge, upon request. The annual and semi-annual reports are available, without charge, upon request. Shareholders in the Funds may make inquiries to the Funds to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable.

Reports and other information about the Funds are available free of charge on the EDGAR Database on the SEC's Internet site at http://www.sec.gov. Copies of this information also may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: [email protected].

SSGA Funds Management, Inc

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

00298405The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Fund Summaries	1
State Street Institutional U.S. Government Money Market Fund	1
State Street Institutional Treasury Plus Money Market Fund	7
Additional Information About Investment Objectives, Principal Strategies and Risks	12
Additional Information About Non-Principal Investment Strategies and Risks	18
Portfolio Holdings Disclosure	20
Management and Organization	21
Shareholder Information	23
Dividends, Distributions and Tax Considerations	29
Financial Intermediary Arrangements	30
Financial Highlights	31