# EDGAR Filing Document

**Accession Number:** 0000889512
**File Stem:** 0001133228-26-006909
**Filing Date:** 2026-4
**Character Count:** 87502
**Document Hash:** 812d9bb62bd0afa7273539f848f227b0
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001133228-26-006909.hdr.sgml**: 20260428

**ACCESSION NUMBER**: 0001133228-26-006909

**CONFORMED SUBMISSION TYPE**: N-CSRS

**PUBLIC DOCUMENT COUNT**: 28

**CONFORMED PERIOD OF REPORT**: 20260228

**FILED AS OF DATE**: 20260428

**DATE AS OF CHANGE**: 20260428

**EFFECTIVENESS DATE**: 20260428

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** LEGG MASON PARTNERS INSTITUTIONAL TRUST
- **CENTRAL INDEX KEY:** 0000889512

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MD
- **FISCAL YEAR END:** 0831

**FILING VALUES:**
- **FORM TYPE:** N-CSRS
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-06740
- **FILM NUMBER:** 26906143

**BUSINESS ADDRESS:**
- **STREET 1:** LEGG MASON & CO., LLC
- **STREET 2:** 620 EIGHTH AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10018
- **BUSINESS PHONE:** 1-877-721-1926

**MAIL ADDRESS:**
- **STREET 1:** LEGG MASON & CO., LLC
- **STREET 2:** 620 EIGHTH AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10018

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** CITIFUNDS INSTITUTIONAL TRUST
- **DATE OF NAME CHANGE:** 19981030

## Series and Classes Contracts Data

### Western Asset Institutional U.S. Treasury Obligations Money Market Fund (Series ID: S000041891)

| Class ID   | Class Name            | Ticker Symbol   |
|:---|:---|:---|
| C000130074 | Institutional Shares  | LUIXX           |
| C000130075 | Administrative Shares | LAOXX           |
| C000130076 | Investor Shares       | LAIXX           |

?xml version='1.0' encoding='ASCII'? 2026-03-18LMM1400_WesternAssetInstitutionalUSTreasuryObligationsMoneyMarketFund_InstitutionalShares_TSRSemiAnnual

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 **811-06740**

 **Legg Mason Partners Institutional Trust**

(Exact name of registrant as specified in charter)

**One Madison Avenue, 17th Floor, New York, NY 10010**

(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: **877-6LM-FUND/656-3863**

Date of fiscal year end: **August 31**

Date of reporting period: **February 28, 2026**

ITEM 1. REPORT TO STOCKHOLDERS.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) The Report to Shareholders is filed herewith

---

| | |
|:---|:---|
| ![image](img448_202405131411777.jpg) | ![image](img456_202405131420813.jpg) |
| **Western Asset Institutional U.S. Treasury Obligations Money Market** **Fund**  | **Western Asset Institutional U.S. Treasury Obligations Money Market** **Fund**  |
| Institutional Shares [LUIXX] | Semi-Annual Shareholder Report \| February 28, 2026  |
| ![image](img450_202407221332340.jpg) |  |

---

This semi-annual shareholder report contains important information about Western Asset Institutional U.S. Treasury Obligations Money Market Fund for the period September 1, 2025, to February 28, 2026.

You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 1-800-625-4554, or 1-203-703-6002.

**WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?** (based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Class Name** | **Costs of a $10,000** **investment** | **Costs paid as a percentage of a** **$10,000 investment**<sup>\*</sup><sup>,</sup><sup>†</sup>  |
| Institutional Shares<sup>1</sup>  | $9 | 0.18% |

---

\* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher. Additional amounts may be voluntarily waived and/or reimbursed from time to time.

† Annualized.

1 The expense table reflects the expenses of both the feeder Fund and the master Fund.

**KEY FUND STATISTICS** (as of February 28, 2026)

---

| | |
|:---|:---|
| **Total Net Assets** | $593215573 |
| **Total Number of Portfolio Holdings (reflects holdings of** **U.S. Treasury Obligations Portfolio)** | 27 |

---

**WHAT DID THE FUND INVEST IN?** (as of February 28, 2026)

**Portfolio Composition**<sup>\*</sup> **(% of Total Investments)**

![image](ts6820img004.jpg)

\* Reflects holdings of U.S. Treasury Obligations Portfolio.

---

| | |
|:---|:---|
| ![image](img1988_202405161833219.jpg) | **WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?** |
| ![image](img1988_202405161833219.jpg) | Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its: |
| ![image](img1988_202405161833219.jpg) | • prospectus • proxy voting information • financial information • holdings • tax information |

---

Western Asset Institutional U.S. Treasury Obligations Money Market Fund PAGE 1 WIO0L-STSR-0426

54.536.88.7 ------

---

| | |
|:---|:---|
| ![image](img448_202405131411777.jpg) | ![image](img456_202405131420813.jpg) |
| **Western Asset Institutional U.S. Treasury Obligations Money Market** **Fund**  | **Western Asset Institutional U.S. Treasury Obligations Money Market** **Fund**  |
| Investor Shares [LAIXX] | Semi-Annual Shareholder Report \| February 28, 2026  |
| ![image](img450_202407221332340.jpg) |  |

---

This semi-annual shareholder report contains important information about Western Asset Institutional U.S. Treasury Obligations Money Market Fund for the period September 1, 2025, to February 28, 2026.

You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 1-800-625-4554, or 1-203-703-6002.

**WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?** (based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Class Name** | **Costs of a $10,000** **investment** | **Costs paid as a percentage of a** **$10,000 investment**<sup>\*</sup><sup>,</sup><sup>†</sup>  |
| Investor Shares<sup>1</sup>  | $12 | 0.23% |

---

\* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher. Additional amounts may be voluntarily waived and/or reimbursed from time to time.

† Annualized.

1 The expense table reflects the expenses of both the feeder Fund and the master Fund.

**KEY FUND STATISTICS** (as of February 28, 2026)

---

| | |
|:---|:---|
| **Total Net Assets** | $593215573 |
| **Total Number of Portfolio Holdings (reflects holdings of** **U.S. Treasury Obligations Portfolio)** | 27 |

---

**WHAT DID THE FUND INVEST IN?** (as of February 28, 2026)

**Portfolio Composition**<sup>\*</sup> **(% of Total Investments)**

![image](ts6821img004.jpg)

\* Reflects holdings of U.S. Treasury Obligations Portfolio.

---

| | |
|:---|:---|
| ![image](img1988_202405161833219.jpg) | **WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?** |
| ![image](img1988_202405161833219.jpg) | Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its: |
| ![image](img1988_202405161833219.jpg) | • prospectus • proxy voting information • financial information • holdings • tax information |

---

Western Asset Institutional U.S. Treasury Obligations Money Market Fund PAGE 1 WIO0I-STSR-0426

54.536.88.7 ------

---

| | |
|:---|:---|
| ![image](img448_202405131411777.jpg) | ![image](img456_202405131420813.jpg) |
| **Western Asset Institutional U.S. Treasury Obligations Money Market** **Fund**  | **Western Asset Institutional U.S. Treasury Obligations Money Market** **Fund**  |
| Administrative Shares [LAOXX] | Semi-Annual Shareholder Report \| February 28, 2026  |
| ![image](img450_202407221332340.jpg) |  |

---

This semi-annual shareholder report contains important information about Western Asset Institutional U.S. Treasury Obligations Money Market Fund for the period September 1, 2025, to February 28, 2026.

You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at 1-800-625-4554, or 1-203-703-6002.

**WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?** (based on a hypothetical $10,000 investment)

---

| | | |
|:---|:---|:---|
| **Class Name** | **Costs of a $10,000** **investment** | **Costs paid as a percentage of a** **$10,000 investment**<sup>\*</sup><sup>,</sup><sup>†</sup>  |
| Administrative Shares<sup>1</sup>  | $20 | 0.39% |

---

\* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher. Additional amounts may be voluntarily waived and/or reimbursed from time to time.

† Annualized.

1 The expense table reflects the expenses of both the feeder Fund and the master Fund.

**KEY FUND STATISTICS** (as of February 28, 2026)

---

| | |
|:---|:---|
| **Total Net Assets** | $593215573 |
| **Total Number of Portfolio Holdings (reflects holdings of** **U.S. Treasury Obligations Portfolio)** | 27 |

---

**WHAT DID THE FUND INVEST IN?** (as of February 28, 2026)

**Portfolio Composition**<sup>\*</sup> **(% of Total Investments)**

![image](ts6819img004.jpg)

\* Reflects holdings of U.S. Treasury Obligations Portfolio.

---

| | |
|:---|:---|
| ![image](img1988_202405161833219.jpg) | **WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?** |
| ![image](img1988_202405161833219.jpg) | Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its: |
| ![image](img1988_202405161833219.jpg) | • prospectus • proxy voting information • financial information • holdings • tax information |

---

Western Asset Institutional U.S. Treasury Obligations Money Market Fund PAGE 1 WIOAD-STSR-0426

54.536.88.7 ------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) Not applicable

ITEM 2. CODE OF ETHICS.

Not applicable.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

Not applicable.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

Not applicable.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

Not applicable.

ITEM 6. SCHEDULE OF INVESTMENTS.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) Please see schedule of investments contained in the Financial Statements and Financial
 Highlights included under Item 7 of this Form N-CSR.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) Not applicable.

ITEM 7. FINANCIAL STATEMENTS AND FINANCIAL HIGHLIGHTS FOR OPEN-END MANAGEMENT INVESTMENT COMPANIES.

![](imgc2cdb6b41.gif)

**Western Asset**

**Institutional U.S. Treasury Obligations Money Market Fund**

**Financial Statements and Other Important Information**

**Semi-Annual** \| February 28, 2026

![](imge72fcc062.gif)

**If you need assistance accessing this content, please reach out to your sales representative or send an email to** accessibility@franklintempleton.com**.**

------

**Table of Contents**

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | |
|:---|:---|
| **[Western Asset Institutional U.S. Treasury Obligations Money Market Fund](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SALSpoke-Header-SAL-Spoke-3248_1)** |  |
| [Statement of Assets and Liabilities](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SALSpoke-Header-SAL-Spoke-3248_1) | **1** |
| [Statement of Operations](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SOPSpoke-Header-SOP-Spoke-3248_1) | **2** |
| [Statements of Changes in Net Assets](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SOCSpoke-Header-SOC-Spoke-3248_1) | **3** |
| [Financial Highlights](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_FIHISpoke-Header-FinancialHighlights-Spoke-3248_1) | **4** |
| [Notes to Financial Statements](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_NTFSpoke-Header-Financialhighlights-Spoke-3248_1) | **7** |
| [Changes in and Disagreements with Accountants](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_TSR-TOCTSRDisclosures-3248_1) | **12** |
| [Results of Meeting(s) of Shareholders](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_TSR-TOCTSRDisclosures-3248_1) | **12** |
| [Remuneration Paid to Directors, Officers and Others](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_TSR-TOCTSRDisclosures-3248_1) | **12** |
| **[U.S. Treasury Obligations Portfolio](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SOI-Header-SOI-3240_1)** |  |
| [Schedule of Investments](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SOI-Header-SOI-3240_1) | **13** |
| [Statement of Assets and Liabilities](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SAL-Header-SAL-3240_1) | **15** |
| [Statement of Operations](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SOP-Header-SOP-3240_1) | **16** |
| [Statements of Changes in Net Assets](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_SOC-Header-SOC-3240_1) | **17** |
| [Financial Highlights](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_FH-Header-Financialhighlights-3240_1) | **18** |

---

**franklintempleton.com**

Financial Statements and Other Important Information — Semi-Annual

------

---

| | |
|:---|:---|
| [Notes to Financial Statements](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_NTF-Header-Notestofinancialstatements-3240_1) | **19** |
| [Changes in and Disagreements with Accountants](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_TSR2-TOCTSRDisclosures-HUB-3240_1) | **23** |
| [Results of Meeting(s) of Shareholders](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_TSR2-TOCTSRDisclosures-HUB-3240_1) | **23** |
| [Remuneration Paid to Directors, Officers and Others](#xx_295fbc8a-4f64-4da6-a377-37d4ace93d15_TSR2-TOCTSRDisclosures-HUB-3240_1) | **23** |

---

**franklintempleton.com**

Financial Statements and Other Important Information — Semi-Annual

------

Statement of Assets and Liabilities (unaudited)

February 28, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | |
|:---|:---|
| **Assets:** |  |
| Investment in U.S. Treasury Obligations Portfolio, at value | &nbsp;&nbsp; $594521142 |
| Prepaid expenses | &nbsp;&nbsp; 21510 |
| **Total Assets** | &nbsp;&nbsp; **594542652** |
| **Liabilities:** |  |
| Distributions payable | &nbsp;&nbsp; 1147371 |
| Service and/or distribution fees payable | &nbsp;&nbsp; 67264 |
| Investment management fee payable | &nbsp;&nbsp; 42954 |
| Payable for Fund shares repurchased | &nbsp;&nbsp; 19506 |
| Trustees' fees payable | &nbsp;&nbsp; 720 |
| Accrued expenses | &nbsp;&nbsp; 49264 |
| **Total Liabilities** | &nbsp;&nbsp; **1327079** |
| **Total Net Assets** | &nbsp;&nbsp; **$593215573** |
| **Net Assets:** |  |
| Par value (Note 5) | &nbsp;&nbsp; $5931 |
| Paid-in capital in excess of par value | &nbsp;&nbsp; 593111453 |
| Total distributable earnings (loss)  | &nbsp;&nbsp; 98189 |
| **Total Net Assets** | &nbsp;&nbsp; **$593215573** |
| **Net Assets:** |  |
| Institutional Shares | &nbsp;&nbsp; $144062599 |
| Investor Shares | &nbsp;&nbsp; $554819 |
| Administrative Shares | &nbsp;&nbsp; $448598155 |
| **Shares Outstanding:** |  |
| Institutional Shares | &nbsp;&nbsp; 144031801 |
| Investor Shares | &nbsp;&nbsp; 554606 |
| Administrative Shares | &nbsp;&nbsp; 448517703 |
| **Net Asset Value:** |  |
| Institutional Shares  | &nbsp;&nbsp; $1.00 |
| Investor Shares  | &nbsp;&nbsp; $1.00 |
| Administrative Shares  | &nbsp;&nbsp; $1.00 |

---

See Notes to Financial Statements.

------

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

Statement of Operations (unaudited)

For the Six Months Ended February 28, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | |
|:---|:---|
| **Investment Income:** |  |
| Income from U.S. Treasury Obligations Portfolio | &nbsp;&nbsp; $11355123 |
| Allocated expenses from U.S. Treasury Obligations Portfolio | &nbsp;&nbsp; (95726)<br>|
| **Total Investment Income** | &nbsp;&nbsp; **11259397** |
| **Expenses:** |  |
| Investment management fee (Note 2) | &nbsp;&nbsp; 716957 |
| Service and/or distribution fees (Notes 2 and 3)  | &nbsp;&nbsp; 448656 |
| Transfer agent fees  | &nbsp;&nbsp; 43034 |
| Registration fees | &nbsp;&nbsp; 29114 |
| Legal fees | &nbsp;&nbsp; 17208 |
| Audit and tax fees | &nbsp;&nbsp; 11345 |
| Trustees' fees | &nbsp;&nbsp; 9145 |
| Shareholder reports | &nbsp;&nbsp; 5007 |
| Fund accounting fees | &nbsp;&nbsp; 4420 |
| Insurance | &nbsp;&nbsp; 1859 |
| Miscellaneous expenses  | &nbsp;&nbsp; 5697 |
| **Total Expenses** | &nbsp;&nbsp; **1292442** |
| Less: Fee waivers and/or expense reimbursements (Notes 2 and 3) | &nbsp;&nbsp; (407488)<br>|
| **Net Expenses** | &nbsp;&nbsp; **884954** |
| **Net Investment Income** | &nbsp;&nbsp; **10374443** |
| **Net Realized Gain on Investments From U.S. Treasury Obligations Portfolio** | &nbsp;&nbsp; **95120** |
| **Increase in Net Assets From Operations** | &nbsp;&nbsp; **$10469563** |

---

See Notes to Financial Statements.

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

Statements of Changes in Net Assets

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | | |
|:---|:---|:---|
| For the Six Months Ended February 28, 2026 (unaudited) <br>and the Year Ended August 31, 2025<br>| 2026 | 2025 |
| **Operations:** |  |  |
| Net investment income  | &nbsp;&nbsp; $10374443 | $23090788 |
| Net realized gain  | &nbsp;&nbsp; 95120 | 1332 |
| **Increase in Net Assets From Operations** | &nbsp;&nbsp; **10469563** | **23092120** |
| **Distributions to Shareholders From (Notes 1 and 4):** |  |  |
| Total distributable earnings | &nbsp;&nbsp; (10374150)<br>| (23090803)<br>|
| **Decrease in Net Assets From Distributions to Shareholders** | &nbsp;&nbsp; **(10374150)**<br>| **(23090803)**<br>|
| **Fund Share Transactions (Note 5):** |  |  |
| Net proceeds from sale of shares  | &nbsp;&nbsp; 1676000261 | 1694219936 |
| Reinvestment of distributions | &nbsp;&nbsp; 1719047 | 4981438 |
| Cost of shares repurchased  | &nbsp;&nbsp; (1703259605)<br>| (1533868072)<br>|
| **Increase (Decrease) in Net Assets From Fund Share** <br> **Transactions**<br>| &nbsp;&nbsp; **(25540297)**<br>| **165333302** |
| **Increase (Decrease) in Net Assets** | &nbsp;&nbsp; **(25444884)**<br>| **165334619** |
| **Net Assets:** |  |  |
| Beginning of period | &nbsp;&nbsp; 618660457 | 453325838 |
| **End of period** | &nbsp;&nbsp; **$593215573** | **$618660457** |

---

See Notes to Financial Statements.

------

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

Financial Highlights

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** |
| Institutional Shares | 2026<sup>1</sup> <br>| 2025 | 2024 | 2023 | 2022 | 2021<sup>2</sup> <br>|
| **Net asset value, beginning of** <br> **period**<br>| $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 |
| **Income (loss) from operations:** | **Income (loss) from operations:** |  |  |  |  |  |
| Net investment income | 0.019 | 0.044 | 0.052 | 0.043 | 0.004 | 0.000 <br><sup>3</sup><br>|
| Net realized gain (loss)<sup>3</sup> <br>| 0.000 | 0.000 | 0.000 | 0.000 | &nbsp;&nbsp; (0.000)<br>| 0.000 |
| **Total income from** <br> **operations**<br>| **0.019** | **0.044** | **0.052** | **0.043** | **0.004** | **0.000** <br><sup>3</sup><br>|
| **Less distributions from:** |  |  |  |  |  |  |
| Net investment income | (0.019)<br>| &nbsp;&nbsp; (0.044)<br>| &nbsp;&nbsp; (0.052)<br>| &nbsp;&nbsp; (0.043)<br>| &nbsp;&nbsp; (0.004)<br>| &nbsp;&nbsp; (0.000 )<sup>3</sup><br>|
| **Total distributions**  | **(0.019)**<br>| &nbsp;&nbsp; **(0.044)**<br>| &nbsp;&nbsp; **(0.052)**<br>| &nbsp;&nbsp; **(0.043)**<br>| &nbsp;&nbsp; **(0.004)**<br>| &nbsp;&nbsp; **(0.000)** <br><sup>3</sup><br>|
| **Net asset value, end of period** | $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 |
| **Total return**<sup>4</sup> <br>| **1.88%**<br>| **4.45%**<br>| **5.33%**<br>| **4.34%**<br>| **0.45%**<br>| **0.02%**<br>|
| **Net assets, end of period (000s)** | $144063 | &nbsp;&nbsp; $136286 | &nbsp;&nbsp; $123523 | &nbsp;&nbsp; $134967 | &nbsp;&nbsp; $7581 | &nbsp;&nbsp; $5127 |
| **Ratios to average net assets:** | **Ratios to average net assets:** |  |  |  |  |  |
| Gross expenses<sup>5</sup> <br>| 0.34 %<sup>6</sup><br>| 0.33<br> %<br>| 0.34<br> %<br>| 0.34<br> %<br>| 0.83<br> %<br>| 0.43<br> %<br>|
| Net expenses<sup>5,7,8</sup> <br>| 0.18 <br><sup>6</sup><br>| 0.18 | 0.18 | 0.18 | 0.13 | 0.07 |
| Net investment income | 3.78 <br><sup>6</sup><br>| 4.33 | 5.21 | 4.55 | 0.47 | 0.01 |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

<sup>1</sup> For the six months ended February 28, 2026 (unaudited).

<sup>2</sup> Per share amounts have been calculated using the average shares method.

<sup>3</sup> Amount represents less than $0.0005 or greater than $(0.0005) per share.

<sup>4</sup> Performance figures may reflect fee waivers and/or expense reimbursements. In the absence of fee waivers and/or expense reimbursements, the total return would have been lower. Past performance is no guarantee of future results. Total returns for periods of less than one year are not annualized. 

<sup>5</sup> Includes the Fund's share of U.S. Treasury Obligations Portfolio's allocated expenses.

<sup>6</sup> Annualized.

<sup>7</sup> As a result of an expense limitation arrangement, the ratio of total annual fund operating expenses, other than interest, brokerage, taxes, extraordinary expenses and acquired fund fees and expenses, to average net assets of Institutional Shares did not exceed 0.18%. This expense limitation arrangement cannot be terminated prior to December 31, 2026 without the Board of Trustees' consent. Additional amounts may be voluntarily waived and/or reimbursed from time to time. 

<sup>8</sup> Reflects fee waivers and/or expense reimbursements.

See Notes to Financial Statements.

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

Financial Highlights (cont'd)

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** |
| Investor Shares | 2026<sup>1</sup> <br>| 2025 | 2024 | 2023 | 2022 | 2021<sup>2</sup> <br>|
| **Net asset value, beginning of period** | $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 |
| **Income (loss) from operations:** | **Income (loss) from operations:** |  |  |  |  |  |
| Net investment income | 0.018 | 0.043 | 0.052 | 0.042 | 0.004 | 0.000 <br><sup>3</sup><br>|
| Net realized gain (loss)<sup>3</sup> <br>| 0.000 | 0.000 | 0.000 | 0.000 | &nbsp;&nbsp; (0.000)<br>| 0.000 |
| **Total income from operations** | **0.018** | **0.043** | **0.052** | **0.042** | **0.004** | **0.000** <br><sup>3</sup><br>|
| **Less distributions from:** |  |  |  |  |  |  |
| Net investment income | (0.018)<br>| &nbsp;&nbsp; (0.043)<br>| &nbsp;&nbsp; (0.052)<br>| &nbsp;&nbsp; (0.042)<br>| &nbsp;&nbsp; (0.004)<br>| &nbsp;&nbsp; (0.000 )<sup>3</sup><br>|
| **Total distributions**  | **(0.018)**<br>| &nbsp;&nbsp; **(0.043)**<br>| &nbsp;&nbsp; **(0.052)**<br>| &nbsp;&nbsp; **(0.042)**<br>| &nbsp;&nbsp; **(0.004)**<br>| &nbsp;&nbsp; **(0.000)** <br><sup>3</sup><br>|
| **Net asset value, end of period** | $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 |
| **Total return**<sup>4</sup> <br>| **1.86%**<br>| **4.40%**<br>| **5.28%**<br>| **4.29%**<br>| **0.42%**<br>| **0.02%**<br>|
| **Net assets, end of period (000s)** | $555 | &nbsp;&nbsp; $549 | &nbsp;&nbsp; $4114 | &nbsp;&nbsp; $6342 | &nbsp;&nbsp; $10274 | &nbsp;&nbsp; $4451 |
| **Ratios to average net assets:** | **Ratios to average net assets:** |  |  |  |  |  |
| Gross expenses<sup>5</sup> <br>| 5.35 %<sup>6</sup><br>| 1.78<br> %<br>| 0.96<br> %<br>| 0.73<br> %<br>| 0.96<br> %<br>| 1.02<br> %<br>|
| Net expenses<sup>5,7,8</sup> <br>| 0.23 <br><sup>6</sup><br>| 0.23 | 0.23 | 0.23 | 0.16 | 0.07 |
| Net investment income | 3.71 <br><sup>6</sup><br>| 4.42 | 5.16 | 4.08 | 0.55 | 0.01 |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

<sup>1</sup> For the six months ended February 28, 2026 (unaudited).

<sup>2</sup> Per share amounts have been calculated using the average shares method.

<sup>3</sup> Amount represents less than $0.0005 or greater than $(0.0005) per share.

<sup>4</sup> Performance figures may reflect fee waivers and/or expense reimbursements. In the absence of fee waivers and/or expense reimbursements, the total return would have been lower. Past performance is no guarantee of future results. Total returns for periods of less than one year are not annualized. 

<sup>5</sup> Includes the Fund's share of U.S. Treasury Obligations Portfolio's allocated expenses.

<sup>6</sup> Annualized.

<sup>7</sup> As a result of an expense limitation arrangement, the ratio of total annual fund operating expenses, other than interest, brokerage, taxes, extraordinary expenses and acquired fund fees and expenses, to average net assets of Investor Shares did not exceed 0.23%. This expense limitation arrangement cannot be terminated prior to December 31, 2026 without the Board of Trustees' consent. Additional amounts may be voluntarily waived and/or reimbursed from time to time. 

<sup>8</sup> Reflects fee waivers and/or expense reimbursements.

See Notes to Financial Statements.

------

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** | **For a share of each class of beneficial interest outstanding throughout each year ended August 31,** <br>**unless otherwise noted:** |
| Administrative Shares | 2026<sup>1</sup> <br>| 2025 | 2024 | 2023 | 2022 | 2021<sup>2</sup> <br>|
| **Net asset value, beginning of period** | $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 |
| **Income (loss) from operations:** | **Income (loss) from operations:** |  |  |  |  |  |
| Net investment income | 0.018 | 0.042 | 0.050 | 0.040 | 0.004 | 0.000 <br><sup>3</sup><br>|
| Net realized gain (loss)<sup>3</sup> <br>| 0.000 | 0.000 | 0.000 | 0.000 | &nbsp;&nbsp; (0.000)<br>| 0.000 |
| **Total income from operations** | **0.018** | **0.042** | **0.050** | **0.040** | **0.004** | **0.000** <br><sup>3</sup><br>|
| **Less distributions from:** |  |  |  |  |  |  |
| Net investment income | (0.018)<br>| &nbsp;&nbsp; (0.042)<br>| &nbsp;&nbsp; (0.050)<br>| &nbsp;&nbsp; (0.040)<br>| &nbsp;&nbsp; (0.004)<br>| &nbsp;&nbsp; (0.000 )<sup>3</sup><br>|
| **Total distributions**  | **(0.018)**<br>| &nbsp;&nbsp; **(0.042)**<br>| &nbsp;&nbsp; **(0.050)**<br>| &nbsp;&nbsp; **(0.040)**<br>| &nbsp;&nbsp; **(0.004)**<br>| &nbsp;&nbsp; **(0.000)** <br><sup>3</sup><br>|
| **Net asset value, end of period** | $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 | &nbsp;&nbsp; $1.000 |
| **Total return**<sup>4</sup> <br>| **1.78%**<br>| **4.24%**<br>| **5.11%**<br>| **4.12%**<br>| **0.36%**<br>| **0.02%**<br>|
| **Net assets, end of period (millions)** | $449 | &nbsp;&nbsp; $482 | &nbsp;&nbsp; $326 | &nbsp;&nbsp; $395 | &nbsp;&nbsp; $382 | &nbsp;&nbsp; $407 |
| **Ratios to average net assets:** | **Ratios to average net assets:** |  |  |  |  |  |
| Gross expenses<sup>5</sup> <br>| 0.52 %<sup>6</sup><br>| 0.52<br> %<br>| 0.53<br> %<br>| 0.52<br> %<br>| 0.52<br> %<br>| 0.51<br> %<br>|
| Net expenses<sup>5,7,8</sup> <br>| 0.39 <br><sup>6</sup><br>| 0.39 | 0.39 | 0.39 | 0.22 | 0.08 |
| Net investment income | 3.57 <br><sup>6</sup><br>| 4.13 | 5.00 | 4.03 | 0.35 | 0.01 |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

<sup>1</sup> For the six months ended February 28, 2026 (unaudited).

<sup>2</sup> Per share amounts have been calculated using the average shares method.

<sup>3</sup> Amount represents less than $0.0005 or greater than $(0.0005) per share.

<sup>4</sup> Performance figures may reflect fee waivers and/or expense reimbursements. In the absence of fee waivers and/or expense reimbursements, the total return would have been lower. Past performance is no guarantee of future results. Total returns for periods of less than one year are not annualized. 

<sup>5</sup> Includes the Fund's share of U.S. Treasury Obligations Portfolio's allocated expenses.

<sup>6</sup> Annualized.

<sup>7</sup> As a result of an expense limitation arrangement, the ratio of total annual fund operating expenses, other than interest, brokerage, taxes, extraordinary expenses and acquired fund fees and expenses, to average net assets of Administrative Shares did not exceed 0.40%. This expense limitation arrangement cannot be terminated prior to December 31, 2026 without the Board of Trustees' consent. Additional amounts may be voluntarily waived and/or reimbursed from time to time. 

<sup>8</sup> Reflects fee waivers and/or expense reimbursements.

See Notes to Financial Statements.

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

Notes to Financial Statements (unaudited)

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**1. Organization and significant accounting policies** 

Western Asset Institutional U.S. Treasury Obligations Money Market Fund (the "Fund") is a separate diversified investment series of Legg Mason Partners Institutional 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 Fund invests all of its investable assets in U.S. Treasury Obligations Portfolio (the "Portfolio"), a separate investment series of Master Portfolio Trust, that has the same investment objective as the Fund.

The financial statements of the Portfolio, including the schedule of investments, are contained elsewhere in this report and should be read in conjunction with the Fund's financial statements.

The Fund follows the accounting and reporting guidance in Financial Accounting Standards Board ("FASB") Accounting Standards Codification Topic 946, Financial Services – Investment Companies ("ASC 946"). The following are significant accounting policies consistently followed by the Fund and are in conformity with U.S. generally accepted accounting principles ("GAAP"), including, but not limited to, ASC 946. 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.** The Fund records its investment in the Portfolio at value. The value of such investment in the Portfolio reflects the Fund's proportionate interest (99.2% at February 28, 2026) in the net assets of the Portfolio.

GAAP establishes a disclosure hierarchy that categorizes the inputs to valuation techniques used to value assets and liabilities at measurement date. The disclosure and valuation of securities held by the Portfolio are discussed in Note 1(a) of the Portfolio's Notes to Financial Statements, which are included elsewhere in this report.

**(b) Investment transactions and investment income.** 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. The Fund also pays certain other expenses which can be directly attributed to the Fund.

**(c) Distributions to shareholders.** Distributions from net investment income on the shares of the Fund are declared each business day and are paid monthly. Distributions of net realized gains, if any, are declared at least annually. Distributions to shareholders of the Fund are recorded on the ex-dividend date and are determined in accordance with income tax regulations, which may differ from GAAP.

------

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**(d) Share class accounting.** Investment income, common expenses and realized gains (losses) on investments are allocated to the various classes of the Fund on the basis of daily net assets of each class. Fees relating to a specific class are charged directly to that share class.

**(e) Federal and other taxes.** It is the Fund's policy to comply with the federal income and excise tax requirements of the Internal Revenue Code of 1986 (the "Code"), as amended, applicable to regulated investment companies. Accordingly, the Fund intends to distribute its taxable income and net realized gains, if any, to shareholders in accordance with timing requirements imposed by the Code. Therefore, no federal or state income tax provision is required in the Fund's financial statements.

Management has analyzed the Fund's tax positions taken on income tax returns for all open tax years and has concluded that as of August 31, 2025, no provision for income tax is required in the Fund's financial statements. The Fund's federal and state income and federal excise tax returns for the prior three fiscal years are subject to examination by the Internal Revenue Service and state departments of revenue.

**(f) Reclassification.** GAAP requires that certain components of net assets be reclassified to reflect permanent differences between financial and tax reporting. These reclassifications have no effect on net assets or net asset value per share.

**2. Investment management agreement and other transactions with affiliates**

Franklin Templeton Fund Adviser, LLC ("FTFA") is the Fund's and the Portfolio's investment manager and Western Asset Management Company, LLC ("Western Asset") is the Fund's and the Portfolio's subadviser. FTFA and Western Asset are indirect, wholly-owned subsidiaries of Franklin Resources, Inc. ("Franklin Resources").

Under the investment management agreement, the Fund pays an investment management fee, calculated daily and paid monthly, in accordance with the following breakpoint schedule:

---

| | |
|:---|:---|
| Average Daily Net Assets | Annual Rate |
| First $1 billion | 0.250<br> %<br>|
| Next $1 billion | 0.225 |
| Next $3 billion | 0.200 |
| Next $5 billion | 0.175 |
| Over $10 billion | 0.150 |

---

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

As a result of expense limitation arrangements between the Fund and FTFA, the ratio of total annual fund operating expenses, other than interest, brokerage, taxes, extraordinary expenses and acquired fund fees and expenses, to average net assets of Institutional Shares, Investor Shares and Administrative Shares did not exceed 0.18%, 0.23% and 0.40%, respectively. These expense limitation arrangements cannot be terminated prior to

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

Notes to Financial Statements (unaudited) (cont'd)

December 31, 2026 without the Board of Trustees' (the "Board"), consent. Additional amounts may be voluntarily waived and/or reimbursed from time to time.

During the six months ended February 28, 2026, fees waived and/or expenses reimbursed amounted to $407,488.

FTFA is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual fund operating expenses have fallen to a level below the expense limitation ("expense cap") in effect at the time the fees were earned or the expenses incurred. In no case will FTFA recapture any amount that would result, on any particular business day of the Fund, in the class' total annual fund operating expenses exceeding the expense cap or any other lower limit then in effect.

Franklin Distributors, LLC ("Franklin Distributors") serves as the Fund's sole and exclusive distributor. Franklin Distributors is an indirect, wholly-owned broker-dealer subsidiary of Franklin Resources.

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. Class specific expenses, waivers and/or expense reimbursements**

The Fund has adopted a Rule 12b-1 shareholder services and distribution plan and under that plan the Fund pays service and/or distribution fees with respect to its Investor Shares and Administrative Shares calculated at the annual rate of 0.10% and 0.20% of the average daily net assets of each class, respectively. Service and/or distribution fees are accrued daily and paid monthly.

For the six months ended February 28, 2026, class specific expenses were as follows:

---

| | | |
|:---|:---|:---|
|  | Service and/or <br>Distribution Fees<br>| Transfer Agent <br>Fees<br>|
| Institutional Shares | &nbsp;&nbsp; — | &nbsp;&nbsp; $14552 |
| Investor Shares | &nbsp;&nbsp; $274 <br><sup>†</sup><br>| &nbsp;&nbsp; 13485 |
| Administrative Shares | &nbsp;&nbsp; 448382 | &nbsp;&nbsp; 14997 |
| **Total** | &nbsp;&nbsp; **$448656** | &nbsp;&nbsp; **$43034** |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

† Amount
 shown is exclusive of waivers. For the six months ended February 28, 2026, the service and/or distribution
 fees waived amounted to $137 for Investor Shares. The Board has determined that, until December
 31, 2026, service and/or distribution fees shall not exceed 0.05% of average daily net assets attributable
 to Investor Shares. This arrangement cannot be terminated prior to December 31, 2026 without the Board's
 consent. Additional amounts may be voluntarily waived or reduced from time to time.

------

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

For the six months ended February 28, 2026, waivers and/or expense reimbursements by class were as follows:

---

| | |
|:---|:---|
|  | Waivers/Expense <br>Reimbursements<br>|
| Institutional Shares | &nbsp;&nbsp; $96577 |
| Investor Shares | &nbsp;&nbsp; 13983 |
| Administrative Shares | &nbsp;&nbsp; 296928 |
| **Total** | &nbsp;&nbsp; **$407488** |

---

**4. Distributions to shareholders by class**

---

| | | |
|:---|:---|:---|
|  | Six Months Ended <br>February 28, 2026<br>| Year Ended <br>August 31, 2025<br>|
| **Net Investment Income:** |  |  |
| Institutional Shares | &nbsp;&nbsp; $2356180 | &nbsp;&nbsp; $6645710 |
| Investor Shares | &nbsp;&nbsp; 10154 | &nbsp;&nbsp; 88209 |
| Administrative Shares | &nbsp;&nbsp; 8007816 | &nbsp;&nbsp; 16356884 |
| **Total** | &nbsp;&nbsp; **$10374150** | &nbsp;&nbsp; **$23090803** |

---

**5. Shares of beneficial interest**

At February 28, 2026, the Trust had an unlimited number of shares of beneficial interest authorized with a par value of $0.00001 per share. The Fund has the ability to issue multiple classes of shares. Each class of shares represents an identical interest and has the same rights, except that each class bears certain direct expenses, including those specifically related to the distribution of its shares.

Transactions in shares of each class were as follows:

---

| | | |
|:---|:---|:---|
|  | &nbsp;&nbsp; Six Months Ended <br>February 28, 2026<br>| &nbsp;&nbsp; Year Ended <br>August 31, 2025<br>|
| **Institutional Shares** |  |  |
| Shares sold | &nbsp;&nbsp;&nbsp; 1071399910 | &nbsp;&nbsp;&nbsp; 892022728 |
| Shares issued on reinvestment | &nbsp;&nbsp;&nbsp; 1710182 | &nbsp;&nbsp;&nbsp; 4904753 |
| Shares repurchased | &nbsp;&nbsp;&nbsp; (1065359087)<br>| &nbsp;&nbsp;&nbsp; (884164681)<br>|
| **Net increase** | &nbsp;&nbsp;&nbsp; **7751005** | &nbsp;&nbsp;&nbsp; **12762800** |
| **Investor Shares** |  |  |
| Shares sold | &nbsp;&nbsp;&nbsp; — | &nbsp;&nbsp;&nbsp; — |
| Shares issued on reinvestment | &nbsp;&nbsp;&nbsp; 8314 | &nbsp;&nbsp;&nbsp; 76685 |
| Shares repurchased | &nbsp;&nbsp;&nbsp; (3041)<br>| &nbsp;&nbsp;&nbsp; (3640779)<br>|
| **Net increase (decrease)** | &nbsp;&nbsp;&nbsp; **5273** | &nbsp;&nbsp;&nbsp; **(3564094)**<br>|
| **Administrative Shares** |  |  |
| Shares sold | &nbsp;&nbsp;&nbsp; 604600351 | &nbsp;&nbsp;&nbsp; 802197208 |
| Shares issued on reinvestment | &nbsp;&nbsp;&nbsp; 551 | &nbsp;&nbsp;&nbsp; — |
| Shares repurchased | &nbsp;&nbsp;&nbsp; (637897477)<br>| &nbsp;&nbsp;&nbsp; (646062612)<br>|
| **Net increase (decrease)** | &nbsp;&nbsp;&nbsp; **(33296575)**<br>| &nbsp;&nbsp;&nbsp; **156134596** |

---

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

Notes to Financial Statements (unaudited) (cont'd)

Because the Fund has maintained a $1.00 net asset value per share from inception, the number of shares sold, shares issued on reinvestment of dividends declared, and shares repurchased is equal to the dollar amount shown in the Statements of Changes in Net Assets for the corresponding fund share transactions.

**6. Operating segments**

The Fund operates as a single operating segment, which is an investment portfolio. A management group assigned to the Fund within the Fund's investment manager serves as the Chief Operating Decision Maker ("CODM") and is responsible for evaluating the Fund's operating results and allocating resources in accordance with the Fund's investment strategy. Internal reporting provided to the CODM aligns with the accounting policies and measurement principles used in the financial statements.

For information regarding segment assets, segment profit or loss, and significant expenses, refer to the Statement of Assets and Liabilities and the Statement of Operations, along with the related Notes to Financial Statements. The Schedule of Investments of the Portfolio provides details of investments that generate returns such as interest, dividends, and realized and unrealized gains or losses. Performance metrics, including expense ratios, are disclosed in the Financial Highlights.

------

Western Asset Institutional U.S. Treasury Obligations Money Market Fund 2026 Semi-Annual Report

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | |
|:---|:---|
| **Changes in and Disagreements with Accountants** | For the period covered by this report |
| Not applicable. |  |
| **Results of Meeting(s) of Shareholders** | For the period covered by this report |
| Not applicable. |  |
| **Remuneration Paid to Directors, Officers and Others** | For the period covered by this report |
| Refer to the financial statements included herein. | Refer to the financial statements included herein. |

---

Western Asset Institutional U.S. Treasury Obligations Money Market Fund

------

Schedule of Investments (unaudited)

February 28, 2026

 **U.S. Treasury Obligations Portfolio**

(Percentages shown based on Portfolio net assets)

---

| | | | | |
|:---|:---|:---|:---|:---|
| Security | Rate | Maturity <br>Date<br>| Face <br>Amount<br>| Value |
| **Short-Term Investments — 91.9%** | **Short-Term Investments — 91.9%** | **Short-Term Investments — 91.9%** | **Short-Term Investments — 91.9%** | **Short-Term Investments — 91.9%** |
| **U.S. Treasury Bills — 33.8%** | **U.S. Treasury Bills — 33.8%** | **U.S. Treasury Bills — 33.8%** | **U.S. Treasury Bills — 33.8%** | **U.S. Treasury Bills — 33.8%** |
| U.S. Treasury Bills | &nbsp;&nbsp; 2.551% | &nbsp;&nbsp; 3/3/26 | &nbsp;&nbsp; $7000000 | &nbsp;&nbsp; $6998551<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 2.989% | &nbsp;&nbsp; 3/5/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9995967<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.481% | &nbsp;&nbsp; 3/12/26 | &nbsp;&nbsp; 21500000 | &nbsp;&nbsp; 21475828<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.567% | &nbsp;&nbsp; 3/17/26 | &nbsp;&nbsp; 15000000 | &nbsp;&nbsp; 14975533<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.559% | &nbsp;&nbsp; 3/19/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9981810<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.609% | &nbsp;&nbsp; 3/24/26 | &nbsp;&nbsp; 30000000 | &nbsp;&nbsp; 29930146<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.599% | &nbsp;&nbsp; 3/26/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9974847<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.744% | &nbsp;&nbsp; 3/31/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9968833<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.650% | &nbsp;&nbsp; 4/2/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9967644<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.728% | &nbsp;&nbsp; 4/9/26 | &nbsp;&nbsp; 5000000 | &nbsp;&nbsp; 4979985<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.672% | &nbsp;&nbsp; 4/14/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9955633<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.614% | &nbsp;&nbsp; 4/16/26 | &nbsp;&nbsp; 15000000 | &nbsp;&nbsp; 14931575<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.685% | &nbsp;&nbsp; 4/21/26 | &nbsp;&nbsp; 5000000 | &nbsp;&nbsp; 4974288<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.647% | &nbsp;&nbsp; 4/23/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9947147<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.565% | &nbsp;&nbsp; 4/28/26 | &nbsp;&nbsp; 15000000 | &nbsp;&nbsp; 14915300<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.674% | &nbsp;&nbsp; 5/7/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9933000<br> <sup>(a)</sup><br>|
| U.S. Treasury Bills | &nbsp;&nbsp; 3.684% | &nbsp;&nbsp; 5/14/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 9925946<br> <sup>(a)</sup><br>|
| **Total U.S. Treasury Bills** | **Total U.S. Treasury Bills** | **Total U.S. Treasury Bills** | **Total U.S. Treasury Bills** | &nbsp;&nbsp; **202832033** |
| **U.S. Treasury Notes — 8.0%** | **U.S. Treasury Notes — 8.0%** | **U.S. Treasury Notes — 8.0%** | **U.S. Treasury Notes — 8.0%** | **U.S. Treasury Notes — 8.0%** |
| U.S. Treasury Notes | &nbsp;&nbsp; 0.750% | &nbsp;&nbsp; 3/31/26 | &nbsp;&nbsp; 5000000 | &nbsp;&nbsp; 4986200<br>|
| U.S. Treasury Notes (3 mo. U.S. Treasury Money <br> Market Yield + 0.150%) | &nbsp;&nbsp; 3.793% | &nbsp;&nbsp; 4/30/26 | &nbsp;&nbsp; 43000000 | &nbsp;&nbsp; 43007776<br> <sup>(b)</sup><br>|
| **Total U.S. Treasury Notes** | **Total U.S. Treasury Notes** | **Total U.S. Treasury Notes** | **Total U.S. Treasury Notes** | &nbsp;&nbsp; **47993976** |
| **Repurchase Agreements — 50.1%** | **Repurchase Agreements — 50.1%** | **Repurchase Agreements — 50.1%** | **Repurchase Agreements — 50.1%** | **Repurchase Agreements — 50.1%** |
| Canadian Imperial Bank of Commerce tri-party <br> repurchase agreement dated 2/27/26; Proceeds at <br> maturity — $20,006,100; (Fully collateralized by <br> U.S. government obligations, 0.125% to 4.500% <br> due 3/31/26 to 2/15/54; Market value — <br> $20,406,231) | &nbsp;&nbsp; 3.660% | &nbsp;&nbsp; 3/2/26 | &nbsp;&nbsp; 20000000 | &nbsp;&nbsp; 20000000<br>|
| Credit Agricole SA tri-party repurchase agreement <br> dated 2/27/26; Proceeds at maturity — <br> $50,015,250; (Fully collateralized by U.S. <br> government obligations, 0.000% to 4.375% due <br> 10/29/26 to 8/15/53; Market value — $51,000,026) | &nbsp;&nbsp; 3.660% | &nbsp;&nbsp; 3/2/26 | &nbsp;&nbsp; 50000000 | &nbsp;&nbsp; 50000000<br>|

---

See Notes to Financial Statements.

------

U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

------

 **U.S. Treasury Obligations Portfolio**

(Percentages shown based on Portfolio net assets)

---

| | | | | |
|:---|:---|:---|:---|:---|
| Security | Rate | Maturity<br> Date<br>| Face<br> Amount<br>| Value |
| **Repurchase Agreements — continued** | **Repurchase Agreements — continued** | **Repurchase Agreements — continued** | **Repurchase Agreements — continued** | **Repurchase Agreements — continued** |
| Fixed Income Clearing Corp. tri-party repurchase <br> agreement dated 2/27/26; Proceeds at maturity — <br> $10,003,050; (Fully collateralized by U.S. <br> government obligations, 3.500% due 1/31/28; <br> Market value — $10,200,072) | &nbsp;&nbsp; 3.660% | &nbsp;&nbsp; 3/2/26 | &nbsp;&nbsp; $10000000 | &nbsp;&nbsp; $10000000<br>|
| Fixed Income Clearing Corp. tri-party repurchase <br> agreement dated 2/27/26; Proceeds at maturity — <br> $95,029,054; (Fully collateralized by U.S. <br> government obligations, 2.500% due 3/31/27; <br> Market value — $96,900,058) | &nbsp;&nbsp; 3.670% | &nbsp;&nbsp; 3/2/26 | &nbsp;&nbsp; 95000000 | &nbsp;&nbsp; 95000000<br>|
| HSBC Bank USA tri-party repurchase agreement <br> dated 2/27/26; Proceeds at maturity — <br> $10,003,033; (Fully collateralized by U.S. <br> government obligations, 1.375% due 8/15/50; <br> Market value — $10,203,127) | &nbsp;&nbsp; 3.640% | &nbsp;&nbsp; 3/2/26 | &nbsp;&nbsp; 10000000 | &nbsp;&nbsp; 10000000<br>|
| JPMorgan Securities LLC tri-party repurchase <br> agreement dated 2/27/26; Proceeds at maturity — <br> $5,001,525; (Fully collateralized by U.S. government <br> obligations, 0.125% to 4.625% due 4/30/28 to <br> 4/30/31; Market value — $5,101,569) | &nbsp;&nbsp; 3.660% | &nbsp;&nbsp; 3/2/26 | &nbsp;&nbsp; 5000000 | &nbsp;&nbsp; 5000000<br>|
| Societe Generale SA tri-party repurchase <br> agreement dated 2/27/26; Proceeds at maturity — <br> $50,015,250; (Fully collateralized by U.S. <br> government obligations, 4.750% due 8/15/55; <br> Market value — $51,000,005) | &nbsp;&nbsp; 3.660% | &nbsp;&nbsp; 3/2/26 | &nbsp;&nbsp; 50000000 | &nbsp;&nbsp; 50000000<br>|
| TD Securities LLC tri-party repurchase agreement <br> dated 2/27/26; Proceeds at maturity — <br> $60,018,350; (Fully collateralized by U.S. <br> government obligations, 1.500% to 3.875% due <br> 2/15/30 to 8/15/34; Market value — $61,200,086) | &nbsp;&nbsp; 3.670% | &nbsp;&nbsp; 3/2/26 | &nbsp;&nbsp; 60000000 | &nbsp;&nbsp; 60000000<br>|
| **Total Repurchase Agreements** | **Total Repurchase Agreements** | **Total Repurchase Agreements** | **Total Repurchase Agreements** | &nbsp;&nbsp; **300000000** |
| **Total Investments — 91.9% (Cost — $550,826,009#)** | **Total Investments — 91.9% (Cost — $550,826,009#)** | **Total Investments — 91.9% (Cost — $550,826,009#)** | **Total Investments — 91.9% (Cost — $550,826,009#)** | &nbsp;&nbsp; **550826009** |
| Other Assets in Excess of Liabilities — 8.1% | Other Assets in Excess of Liabilities — 8.1% | Other Assets in Excess of Liabilities — 8.1% | Other Assets in Excess of Liabilities — 8.1% | &nbsp;&nbsp; 48787560 |
| **Total Net Assets — 100.0%** | **Total Net Assets — 100.0%** | **Total Net Assets — 100.0%** | **Total Net Assets — 100.0%** | &nbsp;&nbsp; **$599613569** |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

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

<sup>(a)</sup> Rate shown represents yield-to-maturity.

<sup>(b)</sup> 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.

U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

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Statement of Assets and Liabilities (unaudited)

February 28, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | |
|:---|:---|
| **Assets:** |  |
| Investments, at value | &nbsp;&nbsp; $250826009 |
| Repurchase agreements, at value | &nbsp;&nbsp; 300000000 |
| Cash | &nbsp;&nbsp; 63544915 |
| Interest receivable | &nbsp;&nbsp; 219132 |
| Prepaid expenses | &nbsp;&nbsp; 17300 |
| **Total Assets** | &nbsp;&nbsp; **614607356** |
| **Liabilities:** |  |
| Payable for securities purchased | &nbsp;&nbsp; 14915300 |
| Trustees' fees payable | &nbsp;&nbsp; 626 |
| Accrued expenses | &nbsp;&nbsp; 77861 |
| **Total Liabilities** | &nbsp;&nbsp; **14993787** |
| **Total Net Assets** | &nbsp;&nbsp; **$599613569** |
| **Represented by:** |  |
| **Paid-in capital** | &nbsp;&nbsp; **$599613569** |

---

See Notes to Financial Statements.

------

U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

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Statement of Operations (unaudited)

For the Six Months Ended February 28, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | |
|:---|:---|
| **Investment Income:** |  |
| **Interest** | &nbsp;&nbsp; **$11454783** |
| **Expenses:** |  |
| Fund accounting fees | &nbsp;&nbsp; 31461 |
| Audit and tax fees | &nbsp;&nbsp; 19556 |
| Trustees' fees | &nbsp;&nbsp; 9096 |
| Interest expense  | &nbsp;&nbsp; 1974 |
| Custody fees | &nbsp;&nbsp; 747 |
| Miscellaneous expenses  | &nbsp;&nbsp; 33755 |
| **Total Expenses** | &nbsp;&nbsp; **96589** |
| **Net Investment Income** | &nbsp;&nbsp; **11358194** |
| **Net Realized Gain on Investments**  | &nbsp;&nbsp; **96068** |
| **Increase in Net Assets From Operations** | &nbsp;&nbsp; **$11454262** |

---

See Notes to Financial Statements.

U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

------

Statements of Changes in Net Assets

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | | |
|:---|:---|:---|
| For the Six Months Ended February 28, 2026 (unaudited) <br>and the Year Ended August 31, 2025<br>| 2026 | 2025 |
| **Operations:** |  |  |
| Net investment income  | &nbsp;&nbsp; $11358194 | $24723631 |
| Net realized gain  | &nbsp;&nbsp; 96068 | 1332 |
| **Increase in Net Assets From Operations** | &nbsp;&nbsp; **11454262** | **24724963** |
| **Capital Transactions:** |  |  |
| Proceeds from contributions | &nbsp;&nbsp; 1569808318 | 1612100834 |
| Value of withdrawals | &nbsp;&nbsp; (1607267044)<br>| (1466189673)<br>|
| **Increase (Decrease) in Net Assets From Capital** <br> **Transactions**<br>| &nbsp;&nbsp; **(37458726)**<br>| **145911161** |
| **Increase (Decrease) in Net Assets** | &nbsp;&nbsp; **(26004464)**<br>| **170636124** |
| **Net Assets:** |  |  |
| Beginning of period | &nbsp;&nbsp; 625618033 | 454981909 |
| **End of period** | &nbsp;&nbsp; **$599613569** | **$625618033** |

---

See Notes to Financial Statements.

------

U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

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Financial Highlights

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| **For the years ended August 31, unless otherwise noted:** | **For the years ended August 31, unless otherwise noted:** | **For the years ended August 31, unless otherwise noted:** | **For the years ended August 31, unless otherwise noted:** | **For the years ended August 31, unless otherwise noted:** | **For the years ended August 31, unless otherwise noted:** | **For the years ended August 31, unless otherwise noted:** |
|  | 2026<sup>1</sup> <br>| &nbsp;&nbsp; 2025 | &nbsp;&nbsp; 2024 | &nbsp;&nbsp; 2023 | &nbsp;&nbsp; 2022 | &nbsp;&nbsp; 2021 |
| **Net assets, end of period (millions)** | $600 | &nbsp;&nbsp; $626 | &nbsp;&nbsp; $455 | &nbsp;&nbsp; $538 | &nbsp;&nbsp; $401 | &nbsp;&nbsp; $417 |
| **Total return**<sup>2</sup> <br>| **1.96%**<br>| **4.60%**<br>| **5.48%**<br>| **4.49%**<br>| **0.54%**<br>| **0.07%**<br>|
| **Ratios to average net assets:** | **Ratios to average net assets:** |  |  |  |  |  |
| Gross expenses | 0.03 %<sup>3</sup><br>| 0.04<br> %<br>| 0.04<br> %<br>| 0.04<br> %<br>| 0.04<br> %<br>| 0.03<br> %<br>|
| Net expenses<sup>4</sup> <br>| 0.03 <br><sup>3</sup><br>| 0.04 | 0.04 | 0.04 | 0.04 | 0.03 |
| Net investment income | 3.92 <br><sup>3</sup><br>| 4.47 | 5.34 | 4.45 | 0.53 | 0.06 |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

<sup>1</sup> For the six months ended February 28, 2026 (unaudited).

<sup>2</sup> 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. Total returns for periods of less than one year are not annualized. 

<sup>3</sup> Annualized.

<sup>4</sup> The investment manager has voluntarily undertaken to limit Portfolio expenses. Such expense limitations may fluctuate daily and are voluntary and temporary and may be terminated by the investment manager at any time without notice. 

See Notes to Financial Statements.

U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

------

Notes to Financial Statements (unaudited)

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**1. Organization and significant accounting policies** 

U.S. Treasury Obligations 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 Board of Trustees (the "Board") to issue beneficial interests in the Portfolio. At February 28, 2026, all investors in the Portfolio were funds advised or administered by the investment manager of the Portfolio and/or its affiliates.

The Portfolio follows the accounting and reporting guidance in Financial Accounting Standards Board ("FASB") Accounting Standards Codification Topic 946, Financial Services – Investment Companies ("ASC 946"). The following are significant accounting policies consistently followed by the Portfolio and are in conformity with U.S. generally accepted accounting principles ("GAAP"), including, but not limited to, ASC 946. 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.

Pursuant to policies adopted by the Board, the Portfolio's manager has been designated as the valuation designee and is responsible for the oversight of the daily valuation process. The Portfolio's manager is assisted by the Global Fund Valuation Committee (the "Valuation Committee"). The Valuation Committee is responsible for making fair value determinations, evaluating the effectiveness of the Portfolio's pricing policies, and reporting to the Board.

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.

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U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

------

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** | **ASSETS** | **ASSETS** | **ASSETS** | **ASSETS** |
| Description | Quoted Prices <br>(Level 1)<br>| Other Significant <br>Observable Inputs <br>(Level 2)<br>| Significant <br>Unobservable <br>Inputs <br>(Level 3)<br>| Total |
| Short-Term Investments† | &nbsp;&nbsp; — | &nbsp;&nbsp; $550826009 | &nbsp;&nbsp; — | &nbsp;&nbsp; $550826009 |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

† 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) Interest income and expenses.** Interest income (including interest income from payment-in-kind securities) consists of interest accrued and discount earned (including both

U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

------

Notes to Financial Statements (unaudited) (cont'd)

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.

**(d) 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.

**(e) 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, 2025, no provision for income tax is required in the Portfolio's financial statements. The Portfolio's federal and state income tax returns for the prior three fiscal years are subject to examination by the Internal Revenue Service and state departments of revenue.

**(f) 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**

Franklin Templeton Fund Adviser, LLC ("FTFA") is the Portfolio's investment manager and Western Asset Management Company, LLC ("Western Asset") is the Portfolio's subadviser. FTFA and Western Asset are indirect, wholly-owned subsidiaries of Franklin Resources, Inc. ("Franklin Resources").

Under the investment management agreement, the Portfolio does not pay an investment management fee.

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

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

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U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

------

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 six months ended February 28, 2026, the Portfolio did not invest in derivative instruments.

**4. Operating segments**

The Portfolio operates as a single operating segment, which is an investment portfolio. A management group assigned to the Portfolio within the Portfolio's investment manager serves as the Chief Operating Decision Maker ("CODM") and is responsible for evaluating the Portfolio's operating results and allocating resources in accordance with the Portfolio's investment strategy. Internal reporting provided to the CODM aligns with the accounting policies and measurement principles used in the financial statements.

For information regarding segment assets, segment profit or loss, and significant expenses, refer to the Statement of Assets and Liabilities and the Statement of Operations, along with the related Notes to Financial Statements. The Portfolio's Schedule of Investments provides details of the Portfolio's investments that generate returns such as interest, dividends, and realized and unrealized gains or losses. Performance metrics, including expense ratios, are disclosed in the Financial Highlights.

U.S. Treasury Obligations Portfolio 2026 Semi-Annual Report

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | |
|:---|:---|
| **Changes in and Disagreements with Accountants** | For the period covered by this report |
| Not applicable. |  |
| **Results of Meeting(s) of Shareholders** | For the period covered by this report |
| Not applicable. |  |
| **Remuneration Paid to Directors, Officers and Others** | For the period covered by this report |
| Refer to the financial statements included herein. | Refer to the financial statements included herein. |

---

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U.S. Treasury Obligations Portfolio

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Western Asset

Institutional U.S. Treasury Obligations Money Market

Fund

**Trustees**

Robert Abeles, Jr.

Jane F. Dasher

Anita L. DeFrantz

Susan B. Kerley

Michael Larson

Ronald L. Olson

Avedick B. Poladian

William E.B. Siart

Chair

Jaynie M. Studenmund

Peter J. Taylor

Jane Trust

**Investment manager**

Franklin Templeton Fund Adviser, LLC

**Subadviser**

Western Asset Management Company, LLC

**Distributor**

Franklin Distributors, LLC

**Custodian**

The Bank of New York Mellon

**Transfer agent**

BNY Mellon Investment

Servicing (US) Inc.

500 Ross Street, 154-0520

Pittsburgh, PA 15262

**Independent registered**

**public accounting firm**

PricewaterhouseCoopers LLP

Baltimore, MD

**Western Asset Institutional U.S. Treasury Obligations Money Market Fund**

The Fund is a separate investment series of Legg Mason Partners Institutional Trust, a Maryland statutory trust.

Western Asset Institutional U.S. Treasury Obligations Money Market Fund

Legg Mason Funds

One Madison Avenue, 17th Floor

New York, NY 10010

The Fund files its complete schedule of portfolio holdings with the Securities and Exchange Commission ("SEC") each month on Form N-MFP. The Fund's reports on Form N-MFP are available on the SEC's website at www.sec.gov. The Fund makes portfolio holdings available to shareholders on its website at www.franklintempleton.com.

Information on how the Fund voted proxies relating to portfolio securities during the prior 12-month period ended June 30th of each year and a description of the policies and procedures that the Fund uses to determine how to vote proxies related to portfolio transactions are available (1) without charge, upon request, by calling the Fund at 1-800-625-4554 or 1-203-703-6002, (2) at www.franklintempleton.com and (3) on the SEC's website at www.sec.gov.

This report is submitted for the general information of the shareholders of Western Asset Institutional U.S. Treasury Obligations Money Market Fund. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by a current prospectus.

**Investors should consider the Fund's investment objectives, risks, charges and expenses carefully before investing. The prospectus contains this and other important information about the Fund. Please read the prospectus carefully before investing.**

www.franklintempleton.com© 2026 Franklin Distributors, LLC, Member FINRA/SIPC. All rights reserved.

------

![](img9d7363ae3.jpg)

**91067-SFSOI 4/26**© 2026 Franklin Templeton. All rights reserved.

------

ITEM 8. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS FOR OPEN-END MANAGEMENT INVESTMENT COMPANIES.

The information is disclosed as part of the Financial Statements included in Item 7 of this Form N-CSR.

ITEM 9. PROXY DISCLOSURES FOR OPEN-END MANAGEMENT INVESTMENT COMPANIES.

The information is disclosed as part of the Financial Statements included in Item 7 of this Form N-CSR.

ITEM 10. REMUNERATION PAID TO DIRECTORS, OFFICERS, AND OTHERS OF OPEN-END MANAGEMENT INVESTMENT COMPANIES.

The information is disclosed as part of the Financial Statements included in Item 7 of this Form N-CSR.

ITEM 11. STATEMENT REGARDING BASIS FOR APPROVAL OF INVESTMENT ADVISORY CONTRACT.

The information is disclosed as part of the Financial Statements included in Item 7 of this Form N-CSR, as applicable.

ITEM 12. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 13. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 14. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

Not applicable.

---

| | |
|:---|:---|
| ITEM 15. | SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS. |

---

There have been no changes to the procedures by which shareholders may recommend nominees to the Registrant's Board of Trustees that would require disclosure herein.

ITEM 16. CONTROLS AND PROCEDURES.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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 period covered by this report that have materially affected
 or are likely to materially affect the Registrant's internal control over financial reporting.

ITEM 17. DISCLOSURE OF SECURITIES LENDING ACTIVITIES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 18. RECOVERY OF ERRONEOUSLY AWARDED COMPENSATION.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) Not applicable.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) Not applicable.

ITEM 19. EXHIBITS.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) (1) Not applicable.

Exhibit 99.CODE ETH

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[(a) (3) Certifications pursuant to section 302 of the Sarbanes-Oxley Act of 2002 attached hereto.](waimmf-efp23650_ex99cert.htm)

Exhibit 99.CERT

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[(b) Certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 attached hereto.](waimmf-efp23650_ex99906cert.htm)

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.

**Legg Mason Partners Institutional Trust**

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| | |
|:---|:---|
| By: | /s/ Jane Trust |
|  | Jane Trust |
|  | Principal Executive Officer |
| Date: | April 27, 2026 |

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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.

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| | |
|:---|:---|
| By: | /s/ Jane Trust |
|  | Jane Trust |
|  | Principal Executive Officer |
| Date: | April 27, 2026 |
| By: | /s/ Christopher Berarducci |
|  | Christopher Berarducci |
|  | Principal Financial Officer |
| Date: | April 27, 2026 |

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## Ex-99.Cert

CERTIFICATIONS PURSUANT TO SECTION 302

EX-99.CERT

**<u>CERTIFICATIONS</u>**

I, Jane Trust, certify that:

&nbsp;&nbsp;&nbsp;&nbsp;1. I
 have reviewed this report on Form N-CSR of **Legg Mason Partners Institutional Trust**;

&nbsp;&nbsp;&nbsp;&nbsp;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;

&nbsp;&nbsp;&nbsp;&nbsp;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;

&nbsp;&nbsp;&nbsp;&nbsp;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:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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

&nbsp;&nbsp;&nbsp;&nbsp;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):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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: | April 27, 2026 | /s/ Jane Trust |
|  |  | Jane Trust |
|  |  | Principal Executive Officer |

---

**<u>CERTIFICATIONS</u>**

I, Christopher Berarducci, certify that:

&nbsp;&nbsp;&nbsp;&nbsp;1. I
 have reviewed this report on Form N-CSR of **Legg Mason Partners Institutional Trust**;

&nbsp;&nbsp;&nbsp;&nbsp;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;

&nbsp;&nbsp;&nbsp;&nbsp;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;

&nbsp;&nbsp;&nbsp;&nbsp;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:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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

&nbsp;&nbsp;&nbsp;&nbsp;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):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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: | April 27, 2026 | /s/ Christopher Berarducci |
|  |  | Christopher Berarducci |
|  |  | Principal Financial Officer |

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## Exhibit 99.906

CERTIFICATIONS PURSUANT TO SECTION 906

EX-99.906CERT

**CERTIFICATION**

**Jane Trust,** Principal Executive Officer, and **Christopher Berarducci,** Principal Financial Officer of **Legg Mason Partners Institutional Trust** (the "Registrant"), each certify to the best of their knowledge that:

&nbsp;&nbsp;&nbsp;&nbsp;1. The Registrant's periodic report on Form N-CSR for the period ended **February 28, 2026** (the "Form N-CSR") fully complies with the requirements of Section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934, as amended; and

&nbsp;&nbsp;&nbsp;&nbsp;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.

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| | |
|:---|:---|
| **Principal Executive Officer** | **Principal Financial Officer** |
| Legg Mason Partners Institutional Trust | Legg Mason Partners Institutional Trust |
| /s/ Jane Trust | /s/ Christopher Berarducci |
| Jane Trust | Christopher Berarducci |
| Date: April 27, 2026 | Date: April 27, 2026 |

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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.