N-CSR/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-10407

Master Portfolio Trust

(Exact name of registrant as specified in charter)

620 Eighth Avenue, 47^th Floor, New York, NY 10018

(Address of principal executive offices) (Zip code)

Marc A. De Oliveira

Franklin Templeton

100 First Stamford Place

Stamford, CT 06902

(Name and address of agent for service)

Registrant’s telephone number, including area code: 1-877-721-1926

Date of fiscal year end: August 31

Date of reporting period: August 31, 2022

ITEM 1. REPORT TO STOCKHOLDERS.

The Annual Report to Stockholders is filed herewith.

Schedule of investments

August 31, 2022

U.S. Treasury Reserves Portfolio

(Percentages shown based on Portfolio net assets)

Security	Rate			Maturity Date		Face Amount		Value
Short-Term Investments — 101.5%
U.S. Treasury Bills — 82.0%
U.S. Cash Management Bill		2.187	%		11/1/22	$	190,000,000	$	189,303,117	(a)
U.S. Cash Management Bill		2.258	%		11/8/22		240,000,000		238,989,067	(a)
U.S. Cash Management Bill		2.550	%		11/15/22		184,255,000		183,291,500	(a)
U.S. Cash Management Bill		2.690	%		11/22/22		75,000,000		74,548,573	(a)
U.S. Cash Management Bill		2.842	%		12/13/22		200,000,000		198,409,223	(a)
U.S. Cash Management Bill		3.053	%		1/3/23		73,710,000		72,954,677	(a)(b)
U.S. Treasury Bills		0.000	%		9/1/22		100,000,000		100,000,000	(a)
U.S. Treasury Bills		1.624	%		9/6/22		575,000,000		574,847,753	(a)
U.S. Treasury Bills		1.190	%		9/8/22		448,140,000		448,023,778	(a)
U.S. Treasury Bills		1.651	%		9/13/22		1,633,279,000		1,632,326,582	(a)
U.S. Treasury Bills		2.082	%		9/15/22		1,520,765,000		1,519,477,952	(a)
U.S. Treasury Bills		2.024	%		9/20/22		1,449,974,000		1,448,382,966	(a)
U.S. Treasury Bills		1.545	%		9/22/22		50,000,000		49,953,815	(a)
U.S. Treasury Bills		1.915	%		9/27/22		1,199,080,000		1,197,398,556	(a)
U.S. Treasury Bills		1.729	%		9/29/22		150,000,000		149,795,833	(a)
U.S. Treasury Bills		1.646	%		10/4/22		632,000,000		631,039,484	(a)
U.S. Treasury Bills		1.603	%		10/6/22		659,600,000		658,566,254	(a)
U.S. Treasury Bills		2.040	%		10/11/22		642,450,000		640,994,492	(a)
U.S. Treasury Bills		1.772	%		10/13/22		402,830,000		401,997,347	(a)
U.S. Treasury Bills		2.345	%		10/18/22		480,000,000		478,538,823	(a)
U.S. Treasury Bills		2.221	%		10/20/22		382,060,000		380,911,801	(a)
U.S. Treasury Bills		2.637	%		10/25/22		340,000,000		338,668,900	(a)
U.S. Treasury Bills		2.043	%		10/27/22		350,000,000		348,896,333	(a)
U.S. Treasury Bills		0.160	%		11/3/22		150,000,000		149,958,000	(a)
U.S. Treasury Bills		2.278	%		11/10/22		418,690,000		416,859,704	(a)
U.S. Treasury Bills		2.654	%		11/17/22		200,000,000		198,883,500	(a)
U.S. Treasury Bills		2.793	%		11/25/22		150,000,000		149,029,584	(a)
U.S. Treasury Bills		2.194	%		12/1/22		450,000,000		447,545,528	(a)
U.S. Treasury Bills		1.735	%		12/8/22		100,000,000		99,534,500	(a)
U.S. Treasury Bills		2.556	%		12/29/22		125,000,000		123,967,014	(a)
U.S. Treasury Bills		2.558	%		1/5/23		200,000,000		198,250,000	(a)
U.S. Treasury Bills		2.753	%		1/12/23		100,000,000		99,008,041	(a)
U.S. Treasury Bills		3.002	%		1/26/23		100,000,000		98,807,667	(a)
U.S. Treasury Bills		2.931	%		2/2/23		145,000,000		143,232,209	(a)
U.S. Treasury Bills		3.132	%		2/9/23		100,000,000		98,640,444	(a)
U.S. Treasury Bills		3.113	%		2/16/23		100,000,000		98,590,667	(a)
Total U.S. Treasury Bills									14,279,623,684

See Notes to Financial Statements.

U.S. Treasury Reserves Portfolio 2022 Annual Report   31

Schedule of investments (cont’d)

August 31, 2022

U.S. Treasury Reserves Portfolio

(Percentages shown based on Portfolio net assets)

Security	Rate			Maturity Date		Face Amount		Value
U.S. Treasury Notes — 19.5%
U.S. Treasury Notes		0.125	%		9/30/22	$	150,000,000	$	149,999,170
U.S. Treasury Notes		1.875	%		9/30/22		100,000,000		100,053,110
U.S. Treasury Notes (3 mo. U.S. Treasury Money Market Yield + 0.055%)		2.956	%		10/31/22		450,000,000		450,006,537	(c)
U.S. Treasury Notes		1.625	%		11/15/22		29,000,000		29,086,990
U.S. Treasury Notes		0.125	%		11/30/22		45,000,000		44,994,770
U.S. Treasury Notes (3 mo. U.S. Treasury Money Market Yield + 0.049%)		2.950	%		1/31/23		527,214,000		527,577,332	(c)
U.S. Treasury Notes (3 mo. U.S. Treasury Money Market Yield + 0.034%)		2.935	%		4/30/23		596,000,000		596,034,337	(c)
U.S. Treasury Notes (3 mo. U.S. Treasury Money Market Yield + 0.029%)		2.930	%		7/31/23		370,000,000		370,005,589	(c)
U.S. Treasury Notes (3 mo. U.S. Treasury Money Market Yield + 0.035%)		2.936	%		10/31/23		693,000,000		693,116,611	(c)
U.S. Treasury Notes (3 mo. U.S. Treasury Money Market Yield - 0.075%)		2.826	%		4/30/24		270,000,000		269,676,318	(c)
U.S. Treasury Notes (3 mo. U.S. Treasury Money Market Yield + 0.037%)		2.938	%		7/31/24		160,000,000		159,889,169	(c)
Total U.S. Treasury Notes									3,390,439,933
Total Investments — 101.5% (Cost — $17,670,063,617#)									17,670,063,617
Liabilities in Excess of Other Assets — (1.5)%									(263,551,638	)
Total Net Assets — 100.0%								$	17,406,511,979

# Aggregate cost for federal income tax purposes is substantially the same.

^(a)  Rate shown represents yield-to-maturity.

^(b)  Securities traded on a when-issued or delayed delivery basis.

^(c)  Variable rate security. Interest rate disclosed is as of the most recent information available. Certain variable rate securities are not based on a published reference rate and spread but are determined by the issuer or agent and are based on current market conditions. These securities do not indicate a reference rate and spread in their description above.

See Notes to Financial Statements.

  32 U.S. Treasury Reserves Portfolio 2022 Annual Report

Statement of assets and liabilities

August 31, 2022

Assets:
Investments, at value	$	17,670,063,617
Cash		51,237
Interest receivable		8,243,524
Total Assets		17,678,358,378
Liabilities:
Payable for securities purchased		271,498,677
Trustees’ fees payable		84,382
Accrued expenses		263,340
Total Liabilities		271,846,399
Total Net Assets	$	17,406,511,979
Represented by:
Paid-in capital	$	17,406,511,979

See Notes to Financial Statements.

U.S. Treasury Reserves Portfolio 2022 Annual Report   33

Statement of operations

For the Year Ended August 31, 2022

Investment Income:
Interest	$	104,739,744
Expenses:
Investment management fee (Note 2)		22,376,715
Trustees’ fees		443,777
Fund accounting fees		322,861
Legal fees		221,982
Custody fees		145,189
Audit and tax fees		29,841
Interest expense		1,341
Miscellaneous expenses		104,688
Total Expenses		23,646,394
Less: Fee waivers and/or expense reimbursements (Note 2)		(22,376,715)
Net Expenses		1,269,679
Net Investment Income		103,470,065
Net Realized Loss on Investments		(1,350,636)
Increase in Net Assets From Operations	$	102,119,429

See Notes to Financial Statements.

  34 U.S. Treasury Reserves Portfolio 2022 Annual Report

Statements of changes in net assets

For the Years Ended August 31,	2022		2021
Operations:
Net investment income	$	103,470,065	$	18,651,955
Net realized loss		(1,350,636)		(92,966)
Increase in Net Assets From Operations		102,119,429		18,558,989
Capital Transactions:
Proceeds from contributions		91,992,079,073		82,563,051,774
Value of withdrawals		(97,288,903,338)		(78,121,461,763)
Increase (Decrease) in Net Assets From Capital Transactions		(5,296,824,265)		4,441,590,011
Increase (Decrease) in Net Assets		(5,194,704,836)		4,460,149,000
Net Assets:
Beginning of year		22,601,216,815		18,141,067,815
End of year	$	17,406,511,979	$	22,601,216,815

See Notes to Financial Statements.

U.S. Treasury Reserves Portfolio 2022 Annual Report   35

Financial highlights

For the years ended August 31:
	2022			2021			2020			2019			2018
Net assets, end of year (millions)		$17,407			$22,601			$18,141			$13,488			$16,386
Total return1		0.52	%		0.10	%		1.08	%		2.33	%		1.50	%
Ratios to average net assets:
Gross expenses		0.11	%		0.11	%		0.11	%		0.11	%		0.11	%
Net expenses2,3		0.01			0.01			0.01			0.01			0.01
Net investment income		0.46			0.10			0.91			2.30			1.47

¹  Performance figures may reflect compensating balance arrangements, fee waivers and/or expense reimbursements. In the absence of compensating balance arrangements, fee waivers and/or expense reimbursements, the total return would have been lower. Past performance is no guarantee of future results.

²  The investment manager, pursuant to the terms of the feeder fund’s investment management agreement, has agreed to waive 0.10% of Portfolio expenses, attributable to the Portfolio’s investment management fee.

Additional amounts may be voluntarily waived and/or reimbursed from time to time.

³  Reflects fee waivers and/or expense reimbursements.

See Notes to Financial Statements.

  36 U.S. Treasury Reserves Portfolio 2022 Annual Report

Notes to financial statements

1. Organization and significant accounting policies

U.S. Treasury Reserves Portfolio (the “Portfolio”) is a separate diversified investment series of Master Portfolio Trust (the “Trust”). The Trust, a Maryland statutory trust, is registered under the Investment Company Act of 1940, as amended (the “1940 Act”), as an open-end management investment company. The Declaration of Trust permits the Trustees to issue beneficial interests in the Portfolio. At August 31, 2022, all investors in the Portfolio were funds advised or administered by the investment manager of the Portfolio and/or its affiliates.

The following are significant accounting policies consistently followed by the Portfolio and are in conformity with U.S. generally accepted accounting principles (“GAAP”). Estimates and assumptions are required to be made regarding assets, liabilities and changes in net assets resulting from operations when financial statements are prepared. Changes in the economic environment, financial markets and any other parameters used in determining these estimates could cause actual results to differ. Subsequent events have been evaluated through the date the financial statements were issued.

(a) Investment valuation. In accordance with Rule 2a-7 under the 1940 Act, money market instruments are valued at amortized cost, which approximates market value. This method involves valuing portfolio securities at their cost and thereafter assuming a constant amortization to maturity of any discount or premium. The Portfolio’s use of amortized cost is subject to its compliance with certain conditions as specified by Rule 2a-7 under the 1940 Act.

The Board of Trustees is responsible for the valuation process and has delegated the supervision of the daily valuation process to the Global Fund Valuation Committee (the “Valuation Committee”). The Valuation Committee, pursuant to the policies adopted by the Board of Trustees, is responsible for making fair value determinations, evaluating the effectiveness of the Portfolio’s pricing policies, and reporting to the Board of Trustees.

The Portfolio uses valuation techniques to measure fair value that are consistent with the market approach and/or income approach, depending on the type of security and the particular circumstance. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable securities. The income approach uses valuation techniques to discount estimated future cash flows to present value.

U.S. Treasury Reserves Portfolio 2022 Annual Report   37

Notes to financial statements (cont’d)

GAAP establishes a disclosure hierarchy that categorizes the inputs to valuation techniques used to value assets and liabilities at measurement date. These inputs are summarized in the three broad levels listed below:

• Level 1 — unadjusted quoted prices in active markets for identical investments

• Level 2 — other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, credit risk, etc.)

• Level 3 — significant unobservable inputs (including the Portfolio’s own assumptions in determining the fair value of investments)

The inputs or methodologies used to value securities are not necessarily an indication of the risk associated with investing in those securities.

The following is a summary of the inputs used in valuing the Portfolio’s assets carried at fair value:

ASSETS
Description	Quoted Prices (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Short-Term Investments†		—	$	17,670,063,617		—	$	17,670,063,617

† See Schedule of Investments for additional detailed categorizations.

(b) Repurchase agreements. The Portfolio may enter into repurchase agreements with institutions that its subadviser has determined are creditworthy. Each repurchase agreement is recorded at cost. Under the terms of a typical repurchase agreement, the Portfolio acquires a debt security subject to an obligation of the seller to repurchase, and of the Portfolio to resell, the security at an agreed-upon price and time, thereby determining the yield during the Portfolio’s holding period. When entering into repurchase agreements, it is the Portfolio’s policy that its custodian or a third party custodian, acting on the Portfolio’s behalf, take possession of the underlying collateral securities, the market value of which, at all times, at least equals the principal amount of the repurchase transaction, including accrued interest. To the extent that any repurchase transaction maturity exceeds one business day, the value of the collateral is marked-to-market and measured against the value of the agreement in an effort to ensure the adequacy of the collateral. If the counterparty defaults, the Portfolio generally has the right to use the collateral to satisfy the terms of the repurchase transaction. However, if the market value of the collateral declines during the period in which the Portfolio seeks to assert its rights or if bankruptcy proceedings are commenced with respect to the seller of the security, realization of the collateral by the Portfolio may be delayed or limited.

(c) Securities traded on a when-issued and delayed delivery basis. The Portfolio may trade securities on a when-issued or delayed delivery basis. In when-issued and delayed delivery transactions, the securities are purchased or sold by the Portfolio with payment and delivery taking place in the future in order to secure what is considered to be an advantageous price and yield to the Portfolio at the time of entering into the transaction.

  38 U.S. Treasury Reserves Portfolio 2022 Annual Report

Purchasing such securities involves risk of loss if the value of the securities declines prior to settlement. These securities are subject to market fluctuations and their current value is determined in the same manner as for other securities.

(d) Interest income and expenses. Interest income (including interest income from payment-in-kind securities) consists of interest accrued and discount earned (including both original issue and market discount adjusted for amortization of premium) on the investments of the Portfolio. Expenses of the Portfolio are accrued daily. The Portfolio bears all costs of its operations other than expenses specifically assumed by the investment manager.

(e) Method of allocation. Net investment income of the Portfolio is allocated pro rata, based on respective ownership interests, among the Fund and other investors in the Portfolio (the “Holders”) at the time of such determination. Gross realized gains and/or losses of the Portfolio are allocated to the Holders in a manner such that the net asset values per share of each Holder, after each such allocation, is closer to the total of all Holders’ net asset values divided by the aggregate number of shares outstanding for all Holders.

(f) Compensating balance arrangements. The Portfolio has an arrangement with its custodian bank whereby a portion of the custodian’s fees is paid indirectly by credits earned on the Portfolio’s cash on deposit with the bank.

(g) Income taxes. The Portfolio is classified as a partnership for federal income tax purposes. As such, each investor in the Portfolio is treated as owner of its proportionate share of the net assets, income, expenses and realized gains and losses of the Portfolio. Therefore, no federal income tax provision is required. It is intended that the Portfolio’s assets will be managed so an investor in the Portfolio can satisfy the requirements of Subchapter M of the Internal Revenue Code.

Management has analyzed the Portfolio’s tax positions taken on income tax returns for all open tax years and has concluded that as of August 31, 2022, no provision for income tax is required in the Portfolio’s financial statements. The Portfolio’s federal and state income tax returns for tax years for which the applicable statutes of limitations have not expired are subject to examination by the Internal Revenue Service and state departments of revenue.

(h) Other. Purchases, maturities and sales of money market instruments are accounted for on the date of the transaction. Realized gains and losses are calculated on the identified cost basis.

2. Investment management agreement and other transactions with affiliates

Legg Mason Partners Fund Advisor, LLC (“LMPFA”) is the Portfolio’s investment manager and Western Asset Management Company, LLC (“Western Asset”) is the Portfolio’s subadviser. LMPFA and Western Asset are indirect, wholly-owned subsidiaries of Franklin Resources, Inc. (“Franklin Resources”).

U.S. Treasury Reserves Portfolio 2022 Annual Report   39

Notes to financial statements (cont’d)

Under the investment management agreement, the Portfolio pays an investment management fee, calculated daily and paid monthly, at an annual rate of 0.10% of the Portfolio’s average daily net assets.

LMPFA provides administrative and certain oversight services to the Portfolio. LMPFA delegates to the subadviser the day-to-day portfolio management of the Portfolio. For its services, LMPFA pays Western Asset a fee monthly, at an annual rate equal to 70% of the net management fee it receives from the Portfolio.

As a result of the investment management agreement between LMPFA and the feeder fund, LMPFA has agreed to waive 0.10% of Portfolio expenses, attributable to the Portfolio’s investment management fee. Additional amounts may be voluntarily waived and/or reimbursed from time to time.

During the year ended August 31, 2022, fees waived and/or expenses reimbursed amounted to $22,376,715.

LMPFA is permitted to recapture amounts waived and/or reimbursed to the Portfolio during the same fiscal year under certain circumstances.

All officers and one Trustee of the Trust are employees of Franklin Resources or its affiliates and do not receive compensation from the Trust.

3. Derivative instruments and hedging activities

During the year ended August 31, 2022, the Portfolio did not invest in derivative instruments.

4. Recent accounting pronouncement

In March 2020, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2020-04, Reference Rate Reform (Topic 848) – Facilitation of the Effects of Reference Rate Reform on Financial Reporting. In January 2021, the FASB issued ASU No. 2021-01, with further amendments to Topic 848. The amendments in the ASUs provide optional temporary accounting recognition and financial reporting relief from the effect of certain types of contract modifications due to the planned discontinuation of the LIBOR and other interbank-offered based reference rates as of the end of 2021 and 2023. The ASUs are effective for certain reference rate-related contract modifications that occur during the period March 12, 2020 through December 31, 2022. Management has reviewed the requirements and believes the adoption of these ASUs will not have a material impact on the financial statements.

  40 U.S. Treasury Reserves Portfolio 2022 Annual Report

5. Other matters

The outbreak of the respiratory illness COVID-19 (commonly referred to as “coronavirus”) has continued to rapidly spread around the world, causing considerable uncertainty for the global economy and financial markets. The ultimate economic fallout from the pandemic, and the long-term impact on economies, markets, industries and individual issuers, are not known. The COVID-19 pandemic could adversely affect the value and liquidity of the Portfolio’s investments, impair the Portfolio’s ability to satisfy withdrawal requests, and negatively impact the Portfolio’s performance. In addition, the outbreak of COVID-19, and measures taken to mitigate its effects, could result in disruptions to the services provided to the Portfolio by its service providers.

*  *  *

The Portfolio’s investments, payment obligations, and financing terms may be based on floating rates, such as the London Interbank Offered Rate, or “LIBOR,” which is the offered rate for short-term Eurodollar deposits between major international banks. On March 5, 2021, the ICE Benchmark Administration, the administrator of LIBOR, stated that it will cease the publication of the overnight and one-, three-, six- and twelve-month USD LIBOR settings immediately following the LIBOR publication on Friday, June 30, 2023. All other LIBOR settings, including the one-week and two-month USD LIBOR settings, have ceased publication as of January 1, 2022. There remains uncertainty regarding the nature of any replacement rate and the impact of the transition from LIBOR on the Portfolio’s transactions and the financial markets generally. As such, the potential effect of a transition away from LIBOR on the Portfolio or the Portfolio’s investments cannot yet be determined.

*  *  *

On February 24, 2022, Russia engaged in military actions in the sovereign territory of Ukraine. The current political and financial uncertainty surrounding Russia and Ukraine may increase market volatility and the economic risk of investing in securities in these countries and may also cause uncertainty for the global economy and broader financial markets. The ultimate fallout and long-term impact from these events are not known. The Portfolio will continue to assess the impact on valuations and liquidity and will take any potential actions needed in accordance with procedures approved by the Board of Trustees.

U.S. Treasury Reserves Portfolio 2022 Annual Report   41

Report of independent registered public accounting firm

To the Board of Trustees of Master Portfolio Trust and Investors of U.S. Treasury Reserves Portfolio

Opinion on the Financial Statements

We have audited the accompanying statement of assets and liabilities, including the schedule of investments, of U.S. Treasury Reserves Portfolio (one of the funds constituting Master Portfolio Trust, referred to hereafter as the “Fund”) as of August 31, 2022, the related statement of operations for the year ended August 31, 2022, the statement of changes in net assets for each of the two years in the period ended August 31, 2022, including the related notes, and the financial highlights for each of the five years in the period ended August 31, 2022 (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Fund as of August 31, 2022, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period ended August 31, 2022 and the financial highlights for each of the five years in the period ended August 31, 2022 in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Fund’s management. Our responsibility is to express an opinion on the Fund’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Fund in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits of these financial statements in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. Our procedures included confirmation of securities owned as of August 31, 2022 by correspondence with the custodian and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

/s/PricewaterhouseCoopers LLP

Baltimore, Maryland

October 20, 2022

We have served as the auditor of one or more investment companies in the Franklin Templeton Group of Funds since 1948.

  42 U.S. Treasury Reserves Portfolio 2022 Annual Report

Board approval of management and subadvisory agreements (unaudited)

The Executive and Contracts Committee of the Board of Trustees (the “Executive and Contracts Committee”) considered the Management Agreement between the Trust and Legg Mason Partners Fund Advisor, LLC (“LMPFA”) with respect to the Fund and the subadvisory agreement between LMPFA and Western Asset Management Company, LLC (“Western Asset” or the “Subadviser”, and together with LMPFA, the “Advisers”) with respect to the Fund (collectively, the “Agreements”) at a meeting held on April 19, 2022. At an in-person meeting held on May 12, 2022, the Executive and Contracts Committee reported to the full Board of Trustees their considerations and recommendation with respect to the Agreements, and the Board of Trustees, including a majority of the Independent Trustees, considered and approved renewal of the Agreements.

In arriving at their decision to approve the renewal of the Agreements, the Trustees met with representatives of the Advisers, including relevant investment advisory personnel; considered a variety of information prepared by the Advisers, materials provided by Broadridge and advice and materials provided by counsel to the Independent Trustees; reviewed performance and expense information for peer groups of comparable funds selected by Broadridge (the “Performance Universe”) and certain other comparable products available from Western Asset or affiliates of Western Asset, including separate accounts managed by Western Asset; and requested and reviewed additional information as necessary. These reviews were in addition to information obtained by the Trustees at their regular quarterly meetings (and various committee meetings) with respect to the Fund’s performance and other relevant matters and related discussions with the Advisers’ personnel. The information received and considered by the Board both in conjunction with the May meeting and at prior meetings was both written and oral. With respect to the Broadridge materials, the Board was provided with a description of the methodology used to determine the similarity of the Fund with the funds included in the Performance Universe. It was noted that while the Board found the Broadridge data generally useful they recognized its limitations, including that the data may vary depending on the end date selected and that the results of the performance comparisons may vary depending on the selection of the peer group and its composition over time. The Board noted that the Fund is a “master fund” in a “master-feeder” structure, in which each feeder fund has the same investment objective and policies as the Fund and invests substantially all of its assets in the Fund. The information provided and presentations made to the Board encompassed the Fund and all funds for which the Board has responsibility, including the following feeder funds in the Fund (each, a “Feeder Fund”): Western Asset Institutional U.S. Treasury Reserves, a series of Legg Mason Partners Institutional Trust, and Western Asset Premier Institutional U.S. Treasury Reserves, a series of Legg Mason Partners Institutional Trust.

As part of their review, the Trustees examined LMPFA’s ability to provide high quality oversight and administrative and shareholder support services to the Fund and the Subadvisers’ ability to provide high quality investment management services to the Fund.

U.S. Treasury Reserves Portfolio   43

Board approval of management and subadvisory agreements (unaudited) (cont’d)

The Trustees considered the experience of LMPFA’s personnel in providing the types of services that LMPFA is responsible for providing to the Fund; the ability of LMPFA to attract and retain capable personnel; and the capability and integrity of LMPFA’s senior management and staff. The Trustees also considered the investment philosophy and research and decision-making processes of the Subadviser; the experience of their key advisory personnel responsible for management of the Fund; the ability of the Subadviser to attract and retain capable research and advisory personnel; the risks to the Advisers associated with sponsoring the Fund (such as entrepreneurial, operational, reputational, litigation and regulatory risk), as well as LMPFA’s and the Subadviser’s risk management processes; the capability and integrity of the Advisers’ senior management and staff; and the level of skill required to manage the Fund. In addition, the Trustees reviewed the quality of the Advisers’ services with respect to regulatory compliance and compliance with the investment policies of the Fund, and conditions that might affect the Advisers’ ability to provide high quality services to the Fund in the future, including their business reputations, financial conditions and operational stabilities. The Board also considered the policies and practices of LMPFA and the Subadviser regarding the selection of brokers and dealers and the execution of portfolio transactions. Based on the foregoing, the Trustees concluded that the Subadviser’s investment process, research capabilities and philosophy were well suited to the Fund given its investment objectives and policies, and that the Advisers would be able to meet any reasonably foreseeable obligations under the Agreements.

The Board reviewed the qualifications, backgrounds and responsibilities of LMPFA’s and Western Asset’s senior personnel and the team of investment professionals primarily responsible for the day-to-day portfolio management of the Fund. The Board also considered, based on its knowledge of LMPFA and its affiliates, the financial resources of Franklin Resources, Inc., the parent organization of the Advisers. The Board recognized the importance of having a fund manager with significant resources.

In considering the performance of the Fund, the Board received and considered performance information for each Feeder Fund as well as for the Performance Universe selected by Broadridge. The Board noted that the Feeder Funds’ performance was the same as the performance of the Fund (except for the effect of fees at the Feeder Fund level), and therefore was relevant to the Board’s consideration of the Fund’s performance. The Board was provided with a description of the methodology used to determine the similarity of the Feeder Funds with the funds included in the Performance Universe. It was noted that while the Board found the Broadridge data generally useful they recognized its limitations, including that the data may vary depending on the end date selected and that the results of the performance comparisons may vary depending on the selection of the peer group and its composition over time. The Board also noted that it had received and discussed with management information throughout the year at periodic intervals comparing each Feeder Fund’s performance against its benchmark and against each Feeder Fund’s peers. In addition, the Board considered each Feeder Fund’s performance in light of overall financial market conditions.

  44 U.S. Treasury Reserves Portfolio

• The information comparing Western Asset Institutional U.S. Treasury Reserves’ performance to that of its Performance Universe, consisting of all funds (including the Feeder Fund) classified as institutional U.S. Treasury money market funds by Broadridge, showed, among other data, that the Feeder Fund’s performance for the 1-period ended December 31, 2021 was at the median and its performance for the 3-, 5- and 10-year periods ended December 31, 2021 was above the median.

• The information comparing Western Asset Premier Institutional U.S. Treasury Reserves’ performance to that of its Performance Universe, consisting of all funds (including the Feeder Fund) classified as institutional U.S. Treasury money market funds by Broadridge, showed, among other data, that the Feeder Fund’s performance for the 1-period ended December 31, 2021 was at the median and its performance for the since inception period ended December 31, 2021 was above the median.

The Trustees also considered the management fee payable by the Fund to LMPFA, total expenses payable by the Fund and the fee that LMPFA pays to the Subadviser. They reviewed information concerning management fees paid to investment advisers of similarly managed funds as well as fees paid by Western Asset’s other clients, including separate accounts managed by Western Asset. The Trustees also noted that the Fund does not pay any management fees directly to the Subadviser because LMPFA pays the Subadviser for services provided to the Fund out of the management fee LMPFA receives from the Fund.

• The information comparing Western Asset Institutional U.S. Treasury Reserves’ Contractual and Actual Management Fees as well as its actual total expense ratio to its expense group, consisting of a group of institutional U.S. Treasury money market funds (including the Feeder Fund) chosen by Broadridge to be comparable to the Feeder Fund, showed that the Feeder Fund’s Contractual Management Fee and the Actual Management Fee were below the median. The Board noted that the Feeder Board approval of management and Fund’s actual total expense ratio was below the median. The Board also considered that the current limitation on the Feeder Fund’s expenses is expected to continue through December 2022.

• The information comparing Western Asset Premier Institutional U.S. Treasury Reserves’ Contractual and Actual Management Fees as well as its actual total expense ratio to its expense group, consisting of a group of institutional U.S. Treasury money market funds (including the Feeder Fund) chosen by Broadridge to be comparable to the Feeder Fund, showed that the Feeder Fund’s Contractual Management Fee was above the median and that the Actual Management Fee was below the median. The Board noted that the Feeder Fund’s actual total expense ratio was below the median. The Board also considered that the current limitation on the Feeder Fund’s expenses is expected to continue through December 2022.

U.S. Treasury Reserves Portfolio   45

Board approval of management and subadvisory agreements (unaudited) (cont’d)

The Trustees further evaluated the benefits of the advisory relationship to the Advisers, including, among others, the profitability of the relationship to the Advisers; the direct and indirect benefits that the Advisers may receive from their relationships with the Fund, including the “fallout benefits,” such as reputational value derived from serving as investment adviser to the Fund; and the affiliation between the Advisers and certain other service providers for the Fund. In that connection, the Board considered that the ancillary benefits that the Advisers receive were reasonable. The Trustees noted that Western Asset does not have soft dollar arrangements.

Finally, the Trustees considered, in light of the profitability information provided by the Advisers, the extent to which economies of scale would be realized by the Advisers as the assets of the Fund grow. The Trustees considered an analysis of the profitability of LMPFA and its affiliates in providing services to the Fund and the Feeder Fund.

• The Board noted that the Western Asset Institutional U.S. Treasury Reserves’ Contractual Management Fee and the Actual Management Fee were below the median of the peer group. The Board also noted the size of the Fund.

• The Board noted that the Western Asset Premier Institutional U.S. Treasury Reserves’ Contractual Management Fee was above the median and that the Actual Management Fee was below the median of the peer group. The Board also noted the size of the Fund.

In their deliberations with respect to these matters, the Independent Trustees were advised by their independent counsel, who is independent, within the meaning of the Securities and Exchange Commission rules regarding the independence of counsel, of the Advisers. The Independent Trustees weighed the foregoing matters in light of the advice given to them by their independent counsel as to the law applicable to the review of investment advisory contracts. In arriving at a decision, the Trustees, including the Independent Trustees, did not identify any single matter as all-important or controlling, and each Trustee may have attributed different weight to the various factors in evaluating the Agreements. The foregoing summary does not detail all the matters considered. The Trustees judged the terms and conditions of the Agreements, including the investment advisory fees, in light of all of the surrounding circumstances.

Based upon their review, the Trustees, including all of the Independent Trustees, determined, in the exercise of their business judgment, that they were generally satisfied with the quality of investment advisory services being provided by the Advisers but would continue to closely monitor the Advisers’ performance; that the fees to be paid to the Advisers under the Agreements were fair and reasonable given the scope and quality of the services rendered by the Advisers; and that approval of the Agreements was in the best interest of the Fund and its shareholders.

  46 U.S. Treasury Reserves Portfolio

Additional information (unaudited)

Information about Trustees and Officers

The business and affairs of U.S. Treasury Reserves Portfolio (the “Portfolio”) are conducted by management under the supervision and subject to the direction of its Board of Trustees. The business address of each Trustee is c/o Jane Trust, Franklin Templeton, 100 International Drive, 11th Floor, Baltimore, Maryland 21202.

Information pertaining to the Trustees and officers of the Portfolio is set forth below. The Portfolio’s registration statement includes additional information about Trustees and is available, without charge, upon request by calling the Portfolio at 1-877-721-1926 or 1-203-703-6002.

Independent Trustees†
Robert Abeles, Jr.
Year of birth	1945
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 2013
Principal occupation(s) during the past five years	Board Member, Great Public Schools Now (since 2018); Senior Vice President Emeritus (since 2016) and formerly, Senior Vice President, Finance and Chief Financial Officer (2009 to 2016) at University of Southern California; Board Member, Excellent Education Development (since 2012)
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	None
Jane F. Dasher
Year of birth	1949
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 1999
Principal occupation(s) during the past five years	Chief Financial Officer, Long Light Capital, LLC, formerly known as Korsant Partners, LLC (a family investment company) (since 1997)
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	Director, Visual Kinematics, Inc. (since 2018)
Anita L. DeFrantz
Year of birth	1952
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 1998
Principal occupation(s) during the past five years	President of Tubman Truth Corp. (since 2015); President Emeritus (since 2015) and formerly, President (1987 to 2015) and Director (1990 to 2015) of LA84 (formerly Amateur Athletic Foundation of Los Angeles); Member (since 1986), Member of the Executive Board (since 2013) and Vice President (since 2017) of the International Olympic Committee
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	None

U.S. Treasury Reserves Portfolio   47

Additional information (unaudited) (cont’d)

Information about Trustees and Officers

Independent Trustees† (cont’d)
Susan B. Kerley
Year of birth	1951
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 1992
Principal occupation(s) during the past five years	Investment Consulting Partner, Strategic Management Advisors, LLC (investment consulting) (since 1990)
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	Director and Trustee (since 1990) and Chairman (since 2017 and 2005 to 2012) of various series of MainStay Family of Funds (66 funds); formerly, Investment Company Institute (ICI) Board of Governors (2006 to 2014); ICI Executive Committee (2011 to 2014); Chairman of the Independent Directors Council (2012 to 2014)
Michael Larson
Year of birth	1959
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 2004
Principal occupation(s) during the past five years	Chief Investment Officer for William H. Gates III (since 1994)4
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	Republic Services, Inc. (since 2009); Fomento Economico Mexicano, SAB (since 2011); Ecolab Inc. (since 2012); formerly, AutoNation, Inc. (2010 to 2018)
Avedick B. Poladian
Year of birth	1951
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 2007
Principal occupation(s) during the past five years	Director and Advisor (since 2017) and former Executive Vice President and Chief Operating Officer (2002 to 2016) of Lowe Enterprises, Inc. (privately held real estate and hospitality firm); formerly, Partner, Arthur Andersen, LLP (1974 to 2002)
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	Occidental Petroleum Corporation (since 2008); California Resources Corporation (2014 to 2021); and Public Storage (since 2010)

  48 U.S. Treasury Reserves Portfolio

Independent Trustees† (cont’d)
William E.B. Siart
Year of birth	1946
Position(s) with Fund	Trustee and Chairman of the Board
Term of office1 and length of time served2	Since 1997 (Chairman of the Board since 2020)
Principal occupation(s) during the past five years	Chairman of Excellent Education Development (since 2000); formerly, Chairman of Great Public Schools Now (2015 to 2020); Trustee of The Getty Trust (since 2005 to 2017); Chairman of Walt Disney Concert Hall, Inc. (1998 to 2006)
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	Member of Board of United States Golf Association, Executive Committee Member (since 2017); Trustee, University of Southern California (since 1994)
Jaynie Miller Studenmund
Year of birth	1954
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 2004
Principal occupation(s) during the past five years	Corporate Board Member and Advisor (since 2004); formerly, Chief Operating Officer of Overture Services, Inc. (publicly traded internet company that created search engine marketing) (2001 to 2004); President and Chief Operating Officer, PayMyBills (internet innovator in bill presentment/payment space) (1999 to 2001); Executive vice president for consumer and business banking for three national financial institutions (1984 to 1997)
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	Director of Pacific Premier Bancorp Inc. and Pacific Premier Bank (since 2019); Director of EXL (operations management and analytics company) (since 2018); Director of CoreLogic, Inc. (information, analytics and business services company) (since 2012); formerly, Director of Pinnacle Entertainment, Inc. (gaming and hospitality company) (2012 to 2018); Director of LifeLock, Inc. (identity theft protection company) (2015 to 2017); Director of Orbitz Worldwide, Inc. (online travel company) (2007 to 2014)
Peter J. Taylor
Year of birth	1958
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 2019
Principal occupation(s) during the past five years	President, ECMC Foundation (nonprofit organization) (since 2014); formerly, Executive Vice President and Chief Financial Officer for University of California system (2009 to 2014)
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	Director of Pacific Mutual Holding Company5 (since 2016); Member of the Board of Trustees of California State University system (since 2015); Ralph M. Parson Foundation (since 2015), Kaiser Family Foundation (since 2012), and Edison International (since 2011)

U.S. Treasury Reserves Portfolio   49

Additional information (unaudited) (cont’d)

Information about Trustees and Officers

Interested Trustee
Ronald L. Olson6
Year of birth	1941
Position(s) with Fund	Trustee
Term of office1 and length of time served2	Since 2005
Principal occupation(s) during the past five years	Partner of Munger, Tolles & Olson LLP (law partnership) (since 1968)
Number of funds in fund complex overseen by Trustee3	51
Other Trusteeships held by Trustee during the past five years	Berkshire Hathaway, Inc. (since 1997)
Interested Trustee and Officer
Jane Trust, CFA7
Year of birth	1962
Position(s) with Fund	Trustee, President and Chief Executive Officer
Term of office1 and length of time served2	Since 2015
Principal occupation(s) during the past five years	Senior Vice President, Fund Board Management, Franklin Templeton (since 2020); Officer and/or Trustee/Director of 129 funds associated with LMPFA or its affiliates (since 2015); President and Chief Executive Officer of LMPFA (since 2015); formerly, Senior Managing Director (2018 to 2020) and Managing Director (2016 to 2018) of Legg Mason & Co., LLC (“Legg Mason & Co.”); Senior Vice President of LMPFA (2015)
Number of funds in fund complex overseen by Trustee3	129
Other Trusteeships held by Trustee during the past five years	None
Additional Officers
Ted P. Becker Franklin Templeton 620 Eighth Avenue, 47th Floor, New York, NY 10018
Year of birth	1951
Position(s) with Fund	Chief Compliance Officer
Term of office1 and length of time served2	Since 2007
Principal occupation(s) during the past five years	Vice President, Global Compliance of Franklin Templeton (since 2020); Chief Compliance Officer of LMPFA (since 2006); Chief Compliance Officer of certain funds associated with Legg Mason & Co. or its affiliates (since 2006); formerly, Director of Global Compliance at Legg Mason, Inc. (2006 to 2020); Managing Director of Compliance of Legg Mason & Co. (2005 to 2020)

  50 U.S. Treasury Reserves Portfolio

Additional Officers (cont’d)
Susan Kerr Franklin Templeton 620 Eighth Avenue,47th Floor, New York, NY 10018
Year of birth	1949
Position(s) with Fund	Chief Anti-Money Laundering Compliance Officer
Term of office1 and length of time served2	Since 2013
Principal occupation(s) during the past five years	Senior Compliance Analyst, Franklin Templeton (since 2020); Chief Anti-Money Laundering Compliance Officer of certain funds associated with Legg Mason & Co. or its affiliates (since 2013) and Anti-Money Laundering Compliance Officer (since 2012), Senior Compliance Officer (since 2011) and Assistant Vice President (since 2010) of Franklin Distributors, LLC; formerly, Assistant Vice President of Legg Mason & Co. (2010 to 2020)
Marc A. De Oliveira Franklin Templeton 100 First Stamford Place, 6th Floor, Stamford, CT 06902
Year of birth	1971
Position(s) with Fund	Secretary and Chief Legal Officer
Term of office1 and length of time served2	Since 2020
Principal occupation(s) during the past five years	Associate General Counsel of Franklin Templeton (since 2020); Assistant Secretary of certain funds associated with Legg Mason & Co. or its affiliates (since 2006); formerly, Managing Director (2016 to 2020) and Associate General Counsel of Legg Mason & Co. (2005 to 2020)
Thomas C. Mandia Franklin Templeton 100 First Stamford Place, 6th Floor, Stamford, CT 06902
Year of birth	1962
Position(s) with Fund	Senior Vice President
Term of office1 and length of time served2	Since 2020
Principal occupation(s) during the past five years	Senior Associate General Counsel of Franklin Templeton (since 2020); Secretary of LMPFA (since 2006); Assistant Secretary of certain funds associated with Legg Mason & Co. or its affiliates (since 2006); Secretary of LM Asset Services, LLC (“LMAS”) (since 2002) and Legg Mason Fund Asset Management, Inc. (“LMFAM”) (since 2013) (formerly registered investment advisers); formerly, Managing Director and Deputy General Counsel of Legg Mason & Co. (2005 to 2020)

U.S. Treasury Reserves Portfolio   51

Additional information (unaudited) (cont’d)

Information about Trustees and Officers

Additional Officers (cont’d)
Christopher Berarducci Franklin Templeton 620 Eighth Avenue, 47th Floor, New York, NY 10018
Year of birth	1974
Position(s) with Fund	Treasurer and Principal Financial Officer
Term of office1 and length of time served2	Since 2019
Principal occupation(s) during the past five years	Vice President, Fund Administration and Reporting, Franklin Templeton (since 2020); Treasurer (since 2010) and Principal Financial Officer (since 2019) of certain funds associated with Legg Mason & Co. or its affiliates; formerly, Managing Director (2020), Director (2015 to 2020), and Vice President (2011 to 2015) of Legg Mason & Co.
Jeanne M. Kelly Franklin Templeton 620 Eighth Avenue, 47th Floor, New York, NY 10018
Year of birth	1951
Position(s) with Fund	Senior Vice President
Term of office1 and length of time served2	Since 2007
Principal occupation(s) during the past five years	U.S. Fund Board Team Manager, Franklin Templeton (since 2020); Senior Vice President of certain funds associated with Legg Mason & Co. or its affiliates (since 2007); Senior Vice President of LMPFA (since 2006); President and Chief Executive Officer of LMAS and LMFAM (since 2015); formerly, Managing Director of Legg Mason & Co. (2005 to 2020); Senior Vice President of LMFAM (2013 to 2015)

† Trustees who are not “interested persons” of the Portfolio within the meaning of Section 2(a)(19) of the Investment Company Act of 1940, as amended (the “1940 Act”).

¹  Each Trustee and officer serves until his or her respective successor has been duly elected and qualified or until his or her earlier death, resignation, retirement or removal.

²  Indicates the earliest year in which the Trustee became a board member for a fund in the Legg Mason fund complex or the officer took such office.

³  Each board member also serves as a Director of Western Asset Investment Grade Income Fund Inc. and a Trustee of Western Asset Premier Bond Fund (closed-end investment companies), which are considered part of the same fund complex. Additionally, each board member serves as a Trustee of Western Asset Inflation-Linked Income Fund and Western Asset Inflation-Linked Opportunities & Income Fund, closed-end investment companies that are part of the same fund complex.

⁴  Mr. Larson is the chief investment officer for William H. Gates III and in that capacity oversees the investments of Mr. Gates and the investments of the Bill and Melinda Gates Foundation Trust (such combined investments are referred to as the “Accounts”). Since 1997, Western Asset has provided discretionary investment advice with respect to one or more Accounts.

⁵  Western Asset and its affiliates provide investment advisory services with respect to registered investment companies sponsored by an affiliate of Pacific Mutual Holding Company (“Pacific Holdings”). Affiliates of Pacific Holdings receive compensation from LMPFA or its affiliates for shareholder or distribution services provided with respect to registered investment companies for which Western Asset or its affiliates serve as investment adviser.

  52 U.S. Treasury Reserves Portfolio

⁶  Mr. Olson is an “interested person” of the Portfolio, as defined in the 1940 Act, because his law firm has provided legal services to Western Asset.

⁷  Ms. Trust is an “interested person” of the Portfolio, as defined in the 1940 Act, because of her position with LMPFA and/or certain of its affiliates.

U.S. Treasury Reserves Portfolio   53

ITEM 2. CODE OF ETHICS.

The registrant has adopted a code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

The Board of Trustees of the registrant has determined that Robert Abeles, Jr., possess the technical attributes identified in Instruction 2(b) of Item 3 to Form N-CSR to qualify an “Audit Committee’s financial experts,” and has designated Mr. Abeles, Jr. as the Audit Committee’s financial experts. Mr. Abeles, Jr. is an “independent” Trustees pursuant to paragraph (a) (2) of Item 3 to Form N-CSR.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

a) Audit Fees. The aggregate fees billed in the last two fiscal year ending August 31, 2021 and August 31, 2022 (the “Reporting Periods”) for professional services rendered by the Registrant’s principal accountant (the “Auditor”) for the audit of the Registrant’s annual financial statements, or services that are normally provided by the Auditor in connection with the statutory and regulatory filings or engagements for the Reporting Periods, were $125,406 in August 31, 2021 and $125,406 in August 31, 2022.

b) Audit-Related Fees. The aggregate fees billed in the Reporting Period for assurance and related services by the Auditor that are reasonably related to the performance of the Registrant’s financial statements were $0 in August 31, 2021 and $0 in August 31, 2022.

(c) Tax Fees. The aggregate fees billed in the Reporting Periods for professional services rendered by the Auditor for tax compliance, tax advice and tax planning (“Tax Services”) were $0 in August 31, 2021 and $39,000 in August 31, 2022. These services consisted of (i) review or preparation of U.S. federal, state, local and excise tax returns; (ii) U.S. federal, state and local tax planning, advice and assistance regarding statutory, regulatory or administrative developments, and (iii) tax advice regarding tax qualification matters and/or treatment of various financial instruments held or proposed to be acquired or held.

There were no fees billed for tax services by the Auditors to service affiliates during the Reporting Periods that required pre-approval by the Audit Committee.

d) All Other Fees.

There was no other fee billed in the Reporting Periods for products and services provided by the Auditor, other than the services reported in paragraphs (a) through (c) for the Item for the Master Portfolio Trust.

All Other Fees. There were no other non-audit services rendered by the Auditor to Legg Mason Partners Fund Advisors, LLC (“LMPFA”), and any entity controlling, controlled by or under common control with LMPFA that provided ongoing services to Master Portfolio Trust requiring pre-approval by the Audit Committee in the Reporting Period.

(e) Audit Committee’s pre–approval policies and procedures described in paragraph (c) (7) of Rule 2-01 of Regulation S-X.

(1) The Charter for the Audit Committee (the “Committee”) of the Board of each registered investment company (the “Fund”) advised by LMPFA or one of their affiliates (each, an

“Adviser”) requires that the Committee shall approve (a) all audit and permissible non-audit services to be provided to the Fund and (b) all permissible non-audit services to be provided by the Fund’s independent auditors to the Adviser and any Covered Service Providers if the engagement relates directly to the operations and financial reporting of the Fund. The Committee may implement policies and procedures by which such services are approved other than by the full Committee.

The Committee shall not approve non-audit services that the Committee believes may impair the independence of the auditors. As of the date of the approval of this Audit Committee Charter, permissible non-audit services include any professional services (including tax services), that are not prohibited services as described below, provided to the Fund by the independent auditors, other than those provided to the Fund in connection with an audit or a review of the financial statements of the Fund. Permissible non-audit services may not include: (i) bookkeeping or other services related to the accounting records or financial statements of the Fund; (ii) financial information systems design and implementation; (iii) appraisal or valuation services, fairness opinions or contribution-in-kind reports; (iv) actuarial services; (v) internal audit outsourcing services; (vi) management functions or human resources; (vii) broker or dealer, investment adviser or investment banking services; (viii) legal services and expert services unrelated to the audit; and (ix) any other service the Public Company Accounting Oversight Board determines, by regulation, is impermissible.

Pre-approval by the Committee of any permissible non-audit services is not required so long as: (i) the aggregate amount of all such permissible non-audit services provided to the Fund, the Adviser and any service providers controlling, controlled by or under common control with the Adviser that provide ongoing services to the Fund (“Covered Service Providers”) constitutes not more than 5% of the total amount of revenues paid to the independent auditors during the fiscal year in which the permissible non-audit services are provided to (a) the Fund, (b) the Adviser and (c) any entity controlling, controlled by or under common control with the Adviser that provides ongoing services to the Fund during the fiscal year in which the services are provided that would have to be approved by the Committee; (ii) the permissible non-audit services were not recognized by the Fund at the time of the engagement to be non-audit services; and (iii) such services are promptly brought to the attention of the Committee and approved by the Committee (or its delegate(s)) prior to the completion of the audit.

(2) For the Master Portfolio Trust, the percentage of fees that were approved by the audit committee, with respect to: Audit-Related Fees were 100% and 100% for August 31, 2021 and August 31, 2022; Tax Fees were 100% and 100% for August 31, 2021 and August 31, 2022; and Other Fees were 100% and 100% for August 31, 2021 and August 31, 2022.

(f) N/A

(g) Non-audit fees billed by the Auditor for services rendered to Master Portfolio Trust, LMPFA and any entity controlling, controlled by, or under common control with LMPFA that provides ongoing services to Master Portfolio Trust during the reporting period were $773,011 in August 31, 2021 and $343,489 in August 31, 2022.

(h) Yes. Master Portfolio Trust’s Audit Committee has considered whether the provision of non-audit services that were rendered to Service Affiliates, which were not pre-approved (not requiring pre-approval), is compatible with maintaining the Accountant’s independence. All services provided by the Auditor to the Master Portfolio Trust or to Service Affiliates, which were required to be pre-approved, were pre-approved as required.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

a) The independent board members are acting as the registrant’s audit committee as specified in Section 3(a)(58)(B) of the Exchange Act. The Audit Committee consists of the following Board members:

Robert Abeles, Jr.

Jane F. Dasher

Anita L. DeFrantz

Susan B. Kerley

Michael Larson

Avedick B. Poladian

William E.B. Siart

Jaynie M. Studenmund

Peter J. Taylor

(b) Not applicable.

ITEM 6. SCHEDULE OF INVESTMENTS.

Included herein under Item 1.

ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

Not applicable.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

Not applicable.

ITEM 11. CONTROLS AND PROCEDURES.

(a) The registrant’s principal executive officer and principal financial officer have concluded that the registrant’s disclosure controls and procedures (as defined in Rule 30a- 3(c) under the Investment Company Act of 1940, as amended (the “1940 Act”)) are effective as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the disclosure controls and procedures required by Rule 30a-3(b) under the 1940 Act and 15d-15(b) under the Securities Exchange Act of 1934.

(b) There were no changes in the registrant’s internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act) that occurred during the second fiscal

quarter of the period covered by this report that have materially affected, or are likely to materially affect the registrant’s internal control over financial reporting.

ITEM 12. DISCLOSURE OF SECURITIES LENDING ACTIVITIES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 13. EXHIBITS.

(a) (1) Code of Ethics attached hereto.

Exhibit 99.CODE ETH

(a) (2) Certifications pursuant to section 302 of the Sarbanes-Oxley Act of 2002 attached hereto.

Exhibit 99.CERT

(b) Certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 attached hereto.

Exhibit 99.906CERT

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this Report to be signed on its behalf by the undersigned, there unto duly authorized.

Master Portfolio Trust
By:	/s/ Jane Trust
	Jane Trust
	Chief Executive Officer
Date:	December 13, 2022

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By:	/s/ Jane Trust
	Jane Trust
	Chief Executive Officer
Date:	December 13, 2022
By:	/s/ Christopher Berarducci
	Christopher Berarducci
	Principal Financial Officer
Date:	December 13, 2022

EX-99.CODE

Code of Conduct for Principal Executive and Financial Officers (SOX)

Covered Officers and Purpose of the Code

The Funds’ code of ethics (the “Code”) for investment companies within the Legg Mason family of mutual funds (each a “Fund,” and collectively, the “Funds”) applies to each Fund’s Principal Executive Officer, Principal Financial Officer, and Controller (the “Covered Officers”) for the purpose of promoting:

• honest and ethical conduct, including ethical handling of actual or apparent conflicts of interest between personal and professional relationships;

• full, fair, accurate, timely and understandable disclosure in reports and documents a registrant files with, or submits to, the Securities and Exchange Commission (“SEC”) and in other public communications made by the Funds;

• compliance with applicable laws and governmental rules and regulations;

• prompt internal reporting of Code violations to appropriate persons identified in the Code; and

• accountability for adherence to the Code.

Each Covered Officer should adhere to a high standard of business ethics and should be sensitive to situations that may give rise to actual as well as apparent conflicts of interest.

Covered Officers Should Ethically Handle Actual and Apparent Conflicts of Interest

A “conflict of interest” occurs when a Covered Officer’s private interest interferes with the interests of, or his or her service to, a Fund. For example, a conflict of interest would arise if a Covered Officer, or a member of his or her family, receives improper personal benefits as a result of his or her position with a Fund.

Certain conflicts of interest arise out of the relationships between Covered Officers and a Fund and already are subject to conflict of interest provisions in the Investment Company Act of 1940 (“Investment Company Act”) and the Investment Advisers Act of 1940 (“Investment Advisers Act”). For example, Covered Officers may not individually engage in certain transactions (such as the purchase or sale of securities or other property) with a Fund because of their status as “affiliated persons” of the Fund. The Funds’ and the investment advisers’ compliance programs and procedures are designed to prevent, or identify and correct, violations of these provisions. This Code does not, and is not intended to, repeat or replace these programs and procedures, and such conflicts fall outside of the parameters of this Code.

Although typically not presenting an opportunity for improper personal benefit, conflicts arise from, or as a result of, the contractual relationship between a Fund and an investment adviser of which Covered Officers are also officers or employees. As a result, this Code recognizes Covered Officers will, in the normal course of their duties (whether formally for a Fund or for the adviser, or for both), be involved in establishing policies and

implementing decisions that will have different effects on the adviser and the Funds. The participation of Covered Officers in such activities is inherent in the contractual relationship between a Fund and an adviser and is consistent with the performance by Covered Officers of their duties as officers of the Funds. Thus, if performed in conformity with the provisions of the Investment Company Act and the Investment Advisers Act, such activities will be deemed to have been handled ethically. In addition, it is recognized by the Funds’ Boards of Directors/Trustees (“Boards”) that Covered Officers may also be officers or employees of one or more other investment companies covered by this or other codes and that such service, by itself does not give rise to a conflict of interest.

Other conflicts of interest are covered by the Code, even if such conflicts of interest are not subject to provisions in the Investment Company Act and the Investment Advisers Act. The following list provides examples of conflicts of interest under the Code, but Covered Officers should keep in mind these examples are not exhaustive. The overarching principle is that the personal interest of a Covered Officer should not be placed improperly before the interest of a Fund.

Each Covered Officer must:

• not use his or her personal influence or personal relationships improperly to influence investment decisions or financial reporting by a Fund;

• not cause a Fund to take action, or fail to take action, for the individual personal benefit of the Covered Officer rather than the benefit the Fund; and,

• not use material non-public knowledge of portfolio transactions made or contemplated for the Trust to trade personally or cause others to trade personally in contemplation of the market effect of such transactions.

There are some actual or potential conflict of interest situations that, if material, should always be discussed with the Chief Compliance Officer (“CCO”) or designate that has been appointed by the Board of the Funds. Examples of these include:

• service as a director on the board of any public company (other than the Funds or their investment advisers or any affiliated person thereof);

• the receipt of any non-nominal gifts (i.e., in excess of $100);

• the receipt of any entertainment from any company with which a Fund has current or prospective business dealings unless such entertainment is business-related, reasonable in cost, appropriate as to time and place, and not so frequent as to raise any question of impropriety;

• any ownership interest in, or any consulting or employment relationship with, any of the Funds’ service providers (other than their investment advisers, or principal underwriter, or any affiliated person thereof);

• a direct or indirect financial interest in commissions, transaction charges or spreads paid by a Fund for effecting portfolio transactions or for selling or redeeming shares other than an interest arising from the Covered Officer’s employment, such as compensation or equity ownership.

Disclosure and Compliance

Each Covered Officer should:

• familiarize him or herself with the disclosure requirements generally applicable to the Funds;

• not knowingly misrepresent, or cause others to misrepresent, facts about a Fund to others, whether within or outside the Fund, including to the Fund’s Directors/Trustees and auditors, and to governmental regulators and self-regulatory organizations; and

• to the extent appropriate within his or her area of responsibility, consult with other officers and employees of the Funds and the advisers with the goal of promoting full, fair, accurate, timely and understandable disclosure in the reports and documents the Funds file with, or submit to, the SEC and in other public communications made by the Funds.

It is the responsibility of each Covered Officer to promote compliance with the standards and restrictions imposed by applicable laws, rules and regulations.

Reporting and Accountability

Each Covered Officer must:

• upon adoption of the Code (or thereafter as applicable, upon becoming a Covered Officer), affirm in writing to the Board that he or she has received, read, and understands the Code;

• annually thereafter affirm to the Board that he or she has complied with the requirements of the Code;

• not retaliate against any other Covered Officer or any employee of the Funds or their advisers or any affiliated persons thereof or service providers of the Funds for reports of potential violations that are made in good faith;

• notify the CCO promptly if he or she knows of any violation of this Code, of which failure to do so is itself a violation; and

• report at least annually, if necessary, any employment position, including officer or directorships, held by the Covered Officer or any immediate family member of a Covered Officer with affiliated persons of or Service Providers to the Funds.

The CCO is responsible for applying this Code to specific situations in which questions are presented and has the authority to interpret this Code in any particular situation. However, approvals or waivers sought by a Covered Officer will be considered by the Compliance Committee or Audit Committee, (the “Committee”) responsible for oversight of the Fund’s code of ethics under Rule 17j-1 under the Investment Company Act. If a Covered Officer seeking an approval or waiver sits on the Committee, the Covered Person shall recuse him or herself from any such deliberations. Any approval or waiver granted by the Committee will be reported promptly to the Chair of the Audit Committees of the Funds.

The Funds will follow these procedures in investigating and enforcing this Code:

• the CCO will take all appropriate action to investigate any potential violations reported to him, which actions may include the use of internal or external counsel, accountants or other personnel;

• if, after such investigation, the CCO believes that no violation has occurred, the CCO is not required to take any further action;

• any matter that the CCO believes is a violation will be reported to the Committee;

• if the Committee concurs that a violation has occurred, it will inform the Board, which will consider appropriate action, which may include review of, and appropriate modifications to, applicable policies and procedures; notification to appropriate personnel of the investment adviser or its board; or a recommendation to dismiss the Covered Officer;

• the Committee will be responsible for granting waivers, as appropriate; and,

• any changes to or waivers of this Code will, to the extent required, be disclosed as provided by SEC rules.

Other Policies and Procedures

This Code shall be the sole code of ethics adopted by the Funds for purposes of Section 406 of the Sarbanes-Oxley Act and the rules and forms applicable to registered investment companies thereunder. Insofar as other policies or procedures of the Funds, the Funds’ advisers, principal underwriter, or other service providers govern or purport to govern the behavior or activities of Covered Officers subject to this Code, they are superseded by this Code to the extent they overlap or conflict with the provisions of this Code. The Funds’ and their investment advisers’ and principal underwriter’s codes of

ethics under Rule 17j-1 under the Investment Company Act are separate requirements applying to Covered Officers and others, and are not part of this Code.

Confidentiality

All reports and records prepared or maintained pursuant to this Code will be considered confidential and shall be maintained and protected accordingly. Except as otherwise required by law or this Code, such matters shall not be disclosed to anyone other than the appropriate Board and Fund counsel, and the board of Directors/Trustees and fund counsel of any other investment company for whom a Covered Officer serves in a similar capacity.

Annual Report

No less than annually, the CCO shall provide the Board with a written report describing any issues having arisen since the prior year’s report.

Internal Use

This Code is intended solely for the internal use by the Funds and does not constitute an admission by or on behalf of any Fund, as to any fact, circumstance or legal consideration.

EX-99.CERT

CERTIFICATIONS PURSUANT TO SECTION 302

EX-99.CERT

CERTIFICATIONS

I, Jane Trust, certify that:

1. I have reviewed this report on Form N-CSR of Master Portfolio Trust – U.S. Treasury Reserves Portfolio;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officers and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: December 13, 2022	/s/ Jane Trust
	Jane Trust
	Chief Executive Officer

CERTIFICATIONS

I, Christopher Berarducci, certify that:

1. I have reviewed this report on Form N-CSR of Master Portfolio Trust – U.S. Treasury Reserves Portfolio;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial information included in this report, and the financial statements on which the financial information is based, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officers and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: December 13, 2022	/s/ Christopher Berarducci
	Christopher Berarducci
	Principal Financial Officer

EX-99.906CT

CERTIFICATIONS PURSUANT TO SECTION 906

EX-99.906CERT

CERTIFICATION

Jane Trust, Chief Executive Officer, and Christopher Berarducci, Principal Financial Officer of Master Portfolio Trust – U.S. Treasury Reserves Portfolio (the “Registrant”), each certify to the best of their knowledge that:

1.    The Registrant’s periodic report on Form N-CSR for the period ended August 31, 2022 (the “Form N-CSR”) fully complies with the requirements of section 15(d) of the Securities Exchange Act of 1934, as amended; and

2.    The information contained in the Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Chief Executive Officer	Principal Financial Officer
Master Portfolio Trust -	Master Portfolio Trust -
U.S. Treasury Reserves Portfolio	U.S. Treasury Reserves Portfolio
/s/ Jane Trust	/s/ Christopher Berarducci
Jane Trust	Christopher Berarducci
Date: December 13, 2022	Date: December 13, 2022

This certification is being furnished to the Securities and Exchange Commission solely pursuant to 18 U.S.C. § 1350 and is not being filed as part of the Form N-CSR with the Commission.