What changed in this filing

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Item 9A. Controls and Procedures

2025-11-25 compared with 2024-12-17 · 73 added, 52 removed, 153 unchanged (45% of the section changed)

5 unchanged sentences

Changes in Internal Control Over Financial Reporting

Other than changes related to the acquisition of the CMS Business, there have been no changes in our internal control over financial reporting (as such term is defined in rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the fiscal quarter ended September 27, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

There have been no changes in our internal control over financial reporting (as such term is defined in rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the fiscal quarter ended October 3, 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Management's Report on Internal Control Over Financial Reporting

This report does not include a report of management’s assessment regarding internal control over financial reporting or an attestation report of our independent registered public accounting firm due to a transition period established by the rules of the SEC for newly public companies.

Our management is responsible for establishing and maintaining adequate internal control over financial reporting and for assessing the effectiveness of internal control over financial reporting.

Internal control over financial reporting is a process designed 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 and includes those policies and procedures that:

• Pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of the assets of the issuer;

• Provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the issuer are being made only in accordance with authorizations of management and directors of the issuer;

• Provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of the issuer’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements.

Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

The Company’s management, with the participation of its CEO and CFO, conducted an evaluation of the effectiveness of our internal control over financial reporting based on the framework and criteria established in Internal Control-Integrated Framework (2013 Framework), issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

Based on this evaluation, our management has concluded that Amentum Holdings Inc.’s internal control over financial reporting was effective as of October 3, 2025.

The effectiveness of the Company’s internal control over financial reporting as of October 3, 2025 has been audited by Ernst & Young LLP, an independent registered public accounting firm, as stated in their report which is set forth below.

Report of Independent Registered Public Accounting Firm

To the Shareholders and Board of Directors of Amentum Holdings, Inc.

Opinion on Internal Control Over Financial Reporting

We have audited Amentum Holdings, Inc.’s internal control over financial reporting as of October 3, 2025, based on criteria established in Internal Control-Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework) (the COSO criteria).

In our opinion, Amentum Holdings, Inc.

(the Company) maintained, in all material respects, effective internal control over financial reporting as of October 3, 2025, based on the COSO criteria.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated balance sheets of the Company as of October 3, 2025 and September 27, 2024, the related consolidated statements of operations, comprehensive income (loss), shareholders’ equity and cash flows for each of the three years in the period ended October 3, 2025, and the related notes, and our report dated November 25, 2025 expressed an unqualified opinion thereon.

Basis for Opinion

The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting included in the accompanying Management’s Report on Internal Control Over Financial Reporting.

Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit.

We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S.

federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB.

Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects.

Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances.

We believe that our audit provides a reasonable basis for our opinion.

Definition and Limitations of Internal Control Over Financial Reporting

A company’s internal control over financial reporting is a process designed 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.

A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company;

(2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company;

and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements.

/s/ Ernst & Young LLP

Tysons, Virginia

November 25, 2025

Other Information

During the three months ended September 27, 2024, neither the Company nor any director or officer of the Company adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as those terms are defined in Regulation S-K, Item 408.

During the three months ended October 3, 2025, neither the Company nor any director or officer of the Company adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as those terms are defined in Regulation S-K, Item 408.

Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

1 unchanged sentence

The Information required by Items 11, 12, 13 and 14 of Part III of Form 10-K has been omitted in reliance on General Instruction G(3) and is incorporated herein by reference to our proxy statement to be filed with the SEC pursuant to Regulation 14A promulgated under the Securities Exchange Act of 1934, as amended, as set forth below.

The following information regarding the Company’s directors and executive officers is provided pursuant to Exchange Act Rule 14a-3(b)(8):

John Heller Steven J.

Chief Executive Officer Executive Chair

Amentum Holdings, Inc.

General Vincent K.

Brooks Benjamin Dickson

Army, Retired Managing Director

American Securities LLC

General Ralph E.

(Ed) Eberhart Alan E.

Air Force, Retired Co-Founder and Chief Executive Officer

Lindsay Goldberg

Leslie Ireland Barbara L.

Former Assistant Secretary of the Treasury for Intelligence Former Partner

and Analysis and the National Intelligence Manager for PricewaterhouseCoopers LLP

Threat Finance for the Office of the Director of National

Rowland Christopher M.T.

Former Senior Vice President and Chief Financial Officer Former Chairman and Chief Executive Officer

Gold Fields Ltd.

Russell Triedman John Vollmer

Managing Partner Former Chief Executive Officer, Amentum

Lindsay Goldberg

Connor Wentzell

American Securities LLC

OFFICERS AND EXECUTIVES

John Heller Steven J.

Chief Executive Officer Executive Chair

Arnette Travis B.

Chief Operating Officer Chief Financial Officer

Sean Mullen Stuart I.

Chief Growth Officer Chief Legal Officer

Chief Technology Officer

Directors, Executive Officers and Corporate Governance

The information required by this Item 10 will be incorporated herein by reference to the Proxy Statement for the 2025 Annual Meeting of Shareholders to be filed within 120 days after the end of the company’s fiscal year.

Except for the specific disclosures below, the information required by this Item 10 is included in our Proxy Statement for the 2026 Annual Meeting of Shareholders to be filed within 120 days after the end of the company’s fiscal year under the headings “Proposal 1 – Election of Directors”, and “Corporate Governance and General Information Concerning the Board of Directors and Committees” and is herein incorporated by reference.

Our Insider Trading Policy is included within the “Corporate Governance and General Information Concerning the Board of Directors and Committees” section of the Proxy Statement for the 2026 Annual Meeting of Shareholders.

Code of Ethics

We have adopted a code of ethics that applies to our principal executive officer, principal financial officer, principal accounting officer and persons performing similar functions.

That code, our Code of Ethics for Senior Financial Officers, is posted in the “Investor Relations – Governance – Governance Documents” section of our website at www.amentum.com and a printed copy of such code will be furnished free of charge to any shareholder who requests a copy.

We intend to disclose any amendment to the Code of Ethics for Senior Financial Officers that relates to any element of the code of ethics definition enumerated in Item 406(b) of Regulation S-K, and any waiver from a provision of the Code of Ethics for Senior Financial Officers granted to any director, principal executive officer, principal financial officer, principal accounting officer, or any other executive officer of the Company, in the “Investor Relations” section of our website at www.amentum.com within four business days following the date of such amendment or waiver.

The information on our website is not incorporated by reference into and is not a part of this report.

Corporate Governance Guidelines

We have adopted a set of corporate governance guidelines in accordance with the requirements of Section 303A of the New York Stock Exchange Listed Company Manual.

That code, our Corporate Governance Guidelines, is posted in the “Investor Relations – Governance – Governance Documents” section of our website at www.amentum.com and a printed copy will be furnished free of charge to any shareholder who requests a copy.

The information on our website is not incorporated by reference into and is not a part of this report.

Executive Compensation

42 unchanged sentences

8-K/A October 3, 2024 4.4

Third Supplemental Indenture, dated as of December 10, 2024, between Amazon Holdco Inc.

Bank Trust Company, National Association, as trustee.

10-Q February 5, 2025 4.1

Description of the Company’s Securities Registered Pursuant to Section 12 of the Exchange Act of 1934.

10-K December 17, 2024 4.5

Credit Agreement, dated as of September 27, 2024, by and among Amentum Holdings, Inc.

38 unchanged sentences

8-K November 13, 2024 10.4

Form of Option Award Agreement for grants under the Amentum Holdings, Inc.

2024 Stock Incentive Plan *

8-K January 30, 2025 10.1

Employment Agreement by and between Steven J.

14 unchanged sentences

Insider Trading Policy

10-K December 17, 2024 19.1

Subsidiaries of the Registrant.

7 unchanged sentences

Policy Relating to Recovery of Erroneously Awarded Compensation

10-K December 17, 2024 97.1

101.INS XBRL Instance Document (the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document)

9 unchanged sentences

AMENTUM HOLDINGS, INC.

December 17, 2024 By:

November 25, 2025 By:

Chief Executive Officer

3 unchanged sentences

Heller Chief Executive Officer and Director

(Principal Executive Officer) December 17, 2024

(Principal Executive Officer) November 25, 2025

/s/ Travis B.

Johnson Chief Financial Officer

(Principal Financial Officer and Principal Accounting Officer) December 17, 2024

(Principal Financial Officer and Principal Accounting Officer) November 25, 2025

/s/ Steven J.

Demetriou Executive Chairman of the Board of Directors December 17, 2024

/s/ Benjamin Dickson Lead Independent Director December 17, 2024

Demetriou Executive Chairman of the Board of Directors November 25, 2025

/s/ Benjamin Dickson Lead Independent Director November 25, 2025

Benjamin Dickson

/s/ General Vincent K.

Brooks Director December 17, 2024

Brooks Director November 25, 2025

General Vincent K.

/s/ General Ralph E.

Eberhart Director December 17, 2024

Eberhart Director November 25, 2025

General Ralph E.

Goldberg Director December 17, 2024

/s/ Leslie Ireland Director December 17, 2024

Goldberg Director November 25, 2025

/s/ Leslie Ireland Director November 25, 2025

Leslie Ireland

/s/ Barbara L.

Loughran Director December 17, 2024

Loughran Director November 25, 2025

/s/ Sandra E.

Rowland Director December 17, 2024

Rowland Director November 25, 2025

/s/ Christopher M.T.

Thompson Director December 17, 2024

Thompson Director November 25, 2025

Christopher M.T.

/s/ Russell Triedman Director December 17, 2024

/s/ Russell Triedman Director November 25, 2025

Russell Triedman

/s/ John Vollmer Director December 17, 2024

/s/ Connor Wentzell Director December 17, 2024

/s/ John Vollmer Director November 25, 2025

/s/ Connor Wentzell Director November 25, 2025

Connor Wentzell

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 9A. Controls and Procedures