# EDGAR Filing Document

**Accession Number:** 0002011286
**File Stem:** 0001104659-25-123126
**Filing Date:** 2025-12
**Character Count:** 5025
**Document Hash:** 2e48da9488097a80cd2047d69dd0f41c
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-123126.hdr.sgml**: 20251219

**ACCESSION NUMBER**: 0001104659-25-123126

**CONFORMED SUBMISSION TYPE**: DEFA14A

**PUBLIC DOCUMENT COUNT**: 4

**FILED AS OF DATE**: 20251219

**DATE AS OF CHANGE**: 20251219

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Amentum Holdings, Inc.
- **CENTRAL INDEX KEY:** 0002011286
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-BUSINESS SERVICES, NEC [7389]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 990622272
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1003

**FILING VALUES:**
- **FORM TYPE:** DEFA14A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42176
- **FILM NUMBER:** 251587629

**BUSINESS ADDRESS:**
- **STREET 1:** 4800 WESTFIELDS BOULEVARD
- **STREET 2:** SUITE 400
- **CITY:** CHANTILLY
- **STATE:** VA
- **ZIP:** 20151
- **BUSINESS PHONE:** 7035790410

**MAIL ADDRESS:**
- **STREET 1:** 4800 WESTFIELDS BOULEVARD
- **STREET 2:** SUITE 400
- **CITY:** CHANTILLY
- **STATE:** VA
- **ZIP:** 20151

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Amazon Holdco Inc.
- **DATE OF NAME CHANGE:** 20240208

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**SCHEDULE 14A**

Proxy Statement Pursuant to Section 14(a) of

the Securities Exchange Act of 1934 (Amendment No.)

Filed by the Registrant ⌧

Filed by a Party other than the Registrant ◻

Check the appropriate box:

◻ Preliminary Proxy Statement

◻ **Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))**

◻ Definitive Proxy Statement

⌧ Definitive Additional Materials

◻ Soliciting Materials Pursuant to §240.14a-12

![](tm2523471d4_defa14img001.jpg)

**AMENTUM HOLDINGS, INC.**

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

⌧ No fee required.

◻ Fee paid previously with preliminary materials.

◻ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

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| &nbsp;&nbsp;![GRAPHIC](tm2523471d4_defa14img002.jpg) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Your Vote Counts! Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V81981-P41695 AMENTUM HOLDINGS, INC. 4800 WESTFIELDS BLVD, SUITE 400 CHANTILLY, VA 20151 AMENTUM HOLDINGS, INC. You invested in AMENTUM HOLDINGS, INC. and it's time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the stockholder meeting to be held on February 6, 2026. Vote Virtually at the Meeting\* February 6, 2026 9:00 a.m. (EST) Virtually at: www.virtualshareholdermeeting.com/AMTM2026 \*Please check the meeting materials for any special requirements for meeting attendance. Get informed before you vote View the Proxy Statement and Form 10-K online OR you can receive a free paper or email copy of the material(s) by requesting prior to January 23, 2026. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. 2026 Annual Meeting Vote by February 5, 2026 11:59 PM EST. For shares held in a Plan, vote by February 3, 2026 11:59 PM EST. |

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| &nbsp;&nbsp;![GRAPHIC](tm2523471d4_defa14img003.jpg) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click "Delivery Settings". Voting Items Board Recommends V81982-P41695 THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. 1. Election of Directors Nominees: 1a. Steven J. Demetriou For 1b. John Heller For 1c. Benjamin Dickson For 1d. Vincent K. Brooks For 1e. Ralph E. Eberhart For 1f. Alan E. Goldberg For 1g. S. Leslie Ireland For 1h. Barbara L. Loughran For 1i. Sandra E. Rowland For 1j. Christopher M.T. Thompson For 1k. Russell Triedman For 1l. John Vollmer For 1m. Connor Wentzell For 2. The ratification of the appointment of Ernst & Young LLP as the Company's independent registered public accounting firm for the Company's fiscal year 2026. For 3. Advisory vote to approve the Company's named executive officer compensation. For NOTE: Such other business as may properly come before the meeting or any adjournment thereof. |

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