# EDGAR Filing Document

**Accession Number:** 0000889512
**File Stem:** 0001655589-26-000411
**Filing Date:** 2026-4
**Character Count:** 6971
**Document Hash:** 863c8570c6befbcca954532d30b97280
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001655589-26-000411.hdr.sgml**: 20260417

**ACCESSION NUMBER**: 0001655589-26-000411

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20260417

**DATE AS OF CHANGE**: 20260417

**EFFECTIVENESS DATE**: 20260417

**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:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-49552
- **FILM NUMBER:** 26869615

**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 SMASh Series Core Plus Completion Fund (Series ID: S000014683)

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|  |  |  |
|:---|:---|:---|
| Class Name                             | Ticker Symbol | Class ID   |
| SMASh Series Core Plus Completion Fund | LMECX         | C000040181 |

---

## Series and Classes Contracts Data

### Western Asset SMASh Series Core Plus Completion Fund (Series ID: S000014683)

| Class ID   | Class Name                             | Ticker Symbol   |
|:---|:---|:---|
| C000040181 | SMASh Series Core Plus Completion Fund | LMECX           |

90522-P1 04/26

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| | |
|:---|:---|
| ![](img_82b2d949604e4f1.jpg) | ![](img_ee6f01cceed34f1.jpg) |

---

**LEGG MASON PARTNERS INSTITUTIONAL TRUST**<br>**SUPPLEMENT DATED APRIL 17, 2026** <br>**TO THE PROSPECTUS AND**<br>**STATEMENT OF ADDITIONAL INFORMATION ("SAI")** <br>**DATED MAY 1, 2025, OF** <br>**WESTERN ASSET SMASH SERIES CORE PLUS COMPLETION FUND (THE "FUND")**

#### All changes described below are effective May 1, 2026.
&nbsp;&nbsp;&nbsp;&nbsp;**I. The following replaces the references to Ryan K. Brist and Walter E. Kilcullen in the section titled "Management – Investment professionals" in the Fund's Prospectus:** 

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| | | |
|:---|:---|:---|
| **Investment professional** | **Title** | **Investment**<br>**professional of**<br>**the fund since** |
| Mark S. Lindbloom | Deputy CIO, <br>Portfolio Manager | May 2026 |
| Amit Chopra | Portfolio Manager | May 2026 |
| Nicholas Mastroianni | Portfolio Manager | May 2026 |
| Rafael Zielonka | Portfolio Manager | May 2026 |

---

&nbsp;&nbsp;&nbsp;&nbsp;**II. The following replaces the references to Ryan K. Brist and Walter E. Kilcullen in the section titled "More on fund management – Investment professionals" in the Fund's Prospectus:** 

------

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| | | |
|:---|:---|:---|
| **Investment professional** | **Title and recent**<br>**biography** | **Investment**<br>**professional of**<br>**the fund since** |
| Mark S. Lindbloom | Deputy CIO, Portfolio Manager and has been employed by Western Asset as an investment professional for at least the past five years. | May 2026 |
| Amit Chopra | Portfolio Manager and has been employed by Western Asset as an investment professional for at least the past five years. | May 2026 |
| Nicholas Mastroianni | Portfolio Manager and has been employed by Western Asset as an investment professional for at least the past five years. | May 2026 |
| Rafael Zielonka | Portfolio Manager and has been employed by Western Asset as an investment professional for at least the past five years. | May 2026 |

---

&nbsp;&nbsp;&nbsp;&nbsp;**III. The following replaces the references to Ryan K. Brist and Walter E. Kilcullen in the table in the section titled "Investment Professionals – Other Accounts Managed by the Investment Professionals" in the Fund's SAI:** 

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **Investment**<br>**Professionals**<br>| **Type of**<br>**Account**<br>| **Number of**<br>**Accounts**<br>**Managed** <br>| **Total** <br>**Assets<br>Managed<br>(Billions)** <br>**($)** <br>| **Number of<br>Accounts<br>Managed for<br>which** <br>**Advisory**<br>**Fee is**<br>**Performance-**<br>**Based** <br>| **Assets<br>Managed for<br>which** <br>**Advisory<br>Fee is<br>Performance-<br>Based<br>(Billions) ($)**<br>|
| Amit <br>Chopra\* | &nbsp;&nbsp;&nbsp;&nbsp;Registered Investment Companies | 9 | 7.14 |  |  |

---

------

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **Investment**<br>**Professionals**<br>| **Type of**<br>**Account**<br>| **Number of**<br>**Accounts**<br>**Managed** <br>| **Total** <br>**Assets<br>Managed<br>(Billions)** <br>**($)** <br>| **Number of<br>Accounts<br>Managed for<br>which** <br>**Advisory**<br>**Fee is**<br>**Performance-**<br>**Based** <br>| **Assets<br>Managed for<br>which** <br>**Advisory<br>Fee is<br>Performance-<br>Based<br>(Billions) ($)**<br>|
|  | &nbsp;&nbsp;&nbsp;&nbsp;Other Pooled Investment Vehicles | 4 | 0.53 |  |  |
|  | &nbsp;&nbsp;&nbsp;&nbsp;Other Accounts | 37 | 16.46 |  |  |
| Mark S. <br>Lindbloom\* | &nbsp;&nbsp;&nbsp;&nbsp;Registered Investment Companies | 13 | 9.91 |  |  |
|  | &nbsp;&nbsp;&nbsp;&nbsp;Other Pooled Investment Vehicles | 11 | 2.52 |  |  |
|  | &nbsp;&nbsp;&nbsp;&nbsp;Other Accounts | 53 | 20.04 |  |  |
| Nicholas <br>Mastroianni\* | &nbsp;&nbsp;&nbsp;&nbsp;Registered Investment Companies | 13 | 9.28 |  |  |
|  | &nbsp;&nbsp;&nbsp;&nbsp;Other Pooled Investment Vehicles | 4 | 0.53 |  |  |
|  | &nbsp;&nbsp;&nbsp;&nbsp;Other Accounts | 32 | 13.43 |  |  |
| Rafael <br>Zielonka\* | &nbsp;&nbsp;&nbsp;&nbsp;Registered Investment Companies | 5 | 4.11 |  |  |
|  | &nbsp;&nbsp;&nbsp;&nbsp;Other Pooled Investment <br>Vehicles | 5 | 1.45 |  |  |
|  | &nbsp;&nbsp;&nbsp;&nbsp;Other Accounts | 4 | 0.73 |  |  |

---

\* The information is as of March 31, 2026.

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**IV. The following replaces the references to Ryan K. Brist and Walter E. Kilcullen in the table in the section titled "Investment Professionals – Investment Professional Securities Ownership" in the Fund's SAI:** 

---

| | |
|:---|:---|
| **Investment Professionals**<br>| **Dollar Range of Ownership of Securities ($)** <br>|
| Amit Chopra\* | &nbsp;&nbsp;&nbsp;None |
| Mark S. Lindbloom\* | &nbsp;&nbsp;&nbsp;None |
| Nicholas Mastroianni\* | &nbsp;&nbsp;&nbsp;None |
| Rafael Zielonka\* | &nbsp;&nbsp;&nbsp;None |

---

\* The information is as of March 31, 2026.

&nbsp;&nbsp;&nbsp;&nbsp;**V. The following footnote is added following each reference to Christopher Kilpatrick and Julien Scholnick in the Fund's Prospectus and SAI:**

\* Effective September 30, 2026, Christopher Kilpatrick and Julien Scholnick will each step down as a member of the investment professional team for the fund.

#### Please retain this supplement for future reference.

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