Amentum Holdings Inc

This summary highlights certain information contained elsewhere in this proxy statement. The summary does

not contain all of the information that you should consider, and you should review our Annual Report on Form

10-K for the fiscal year ended September 27, 2024 (the “Annual Report”) and the entire proxy statement

carefully before voting.

Unless the context otherwise indicates or requires, as used in this proxy statement, references to: (i)

“Amentum,” the “Company,” “we,” “us,” “our,” or our “company” refer to Amentum Holdings, Inc., its consolidated

subsidiaries and predecessors; (ii) “our Board” or “the Board” means the Board of Directors of the Company; (iii)

“stockholder” means holders of our common stock; (iv) “fiscal,” refers to our fiscal years ended the closest

Friday to September 30; and (v) “you,” “your,” “yours,” or other words of similar import in this proxy statement

refers to stockholders entitled to vote on the matters to be presented at the 2025 Annual Meeting of

Stockholders (the "Annual Meeting").

2025 Annual Meeting of Stockholders

Date and Time: March 5, 2025 at 11:00 a.m. (EST)

Place: Virtual meeting at www.virtualshareholdermeeting.com/AMTM2025

Record date: January 7, 2025

Admission: Our 2025 Annual Meeting of Stockholders will be a virtual meeting conducted solely online and

can be attended by visiting www.virtualshareholdermeeting.com/AMTM2025. To participate in

the Annual Meeting, you will need the control number located on your proxy card or the

instructions that accompanied your proxy materials. If you plan to participate in the virtual

meeting, please see "Important Information about Annual Meeting and Proxy Procedures."

Voting Matters and Board Recommendations

Stockholders are being asked to vote on the following matters at the 2025 Annual Meeting of Stockholders:

How to Vote

Stockholders as of the record date may vote electronically at the virtual meeting or vote in advance by

submitting a proxy by Internet, telephone, or mail as follows:

Background on the Transaction that Created Amentum

On September 27, 2024, Amentum became a public company through the consummation of the spin-off of

Jacobs Solutions Inc.'s ("Jacobs") Critical Missions Solutions business and portions of Jacobs' Divergent

Solutions business (together, the "CMS Business") and merger with Amentum Parent Holdings LLC (including

its affiliates and subsidiaries, “Legacy Amentum”) in a tax-efficient Reverse Morris Trust transaction (collectively,

the "Transaction"). Prior to the spin-off, the CMS Business reorganized under a newly formed company named

Amazon Holdco Inc. (“CMS”) and distributed a $911 million cash dividend payment to Jacobs, who then

distributed prior to the merger approximately 80.95% of the outstanding shares of CMS common stock on a pro

rata basis to Jacobs’ shareholders. In connection with the completion of the merger, CMS was renamed

Amentum Holdings, Inc. On September 30, 2024, Amentum began trading on the New York Stock Exchange

under the ticker symbol “AMTM”.

Because Amentum's Board of Directors was appointed in connection with the closing of the Transaction at the

end of fiscal year 2024, the Board and its committees did not meet in fiscal year 2024. Accordingly, this proxy

statement will provide information about Amentum's governance policies and practices but will not report

historical activities of the Board and its committees.

Amentum's governance is subject to the provisions of our amended and restated certificate of incorporation, our

amended and restated bylaws, and a stockholders agreement that Amentum entered into with Amentum Joint

Venture L.P. (the former owner of Amentum Parent Holdings LLC; hereinafter "Amentum Equityholder" and

including, where relevant, Sponsor Stockholder as defined below) in connection with the Transaction (the

“Stockholders Agreement”). The key provisions in these documents relating to the governance of Amentum are

summarized in the information statement filed as Exhibit 99.1 to the Current Report on Form 8-K of Amazon

Holdco Inc. (now known as Amentum Holdings, Inc.), filed with the Securities and Exchange Commission (the

“SEC”) on September 18, 2024 (the "Information Statement").

Company Performance and Highlights

Performance highlights from Amentum's fiscal year 2024 include:1

•GAAP Revenues grew 7% year-over-year to $8.4 billion

•GAAP Net Loss of $82 million

•Pro Forma Revenues grew 4%, year-over-year, to $13.9 billion

•Pro Forma Net Income of $32 million

•Pro Forma Adjusted EBITDA grew 7%, year-over-year, to $1,052 million

•Pro Forma Adjusted EBITDA Margin grew 20 basis points, year-over-year, to 7.6%

1 This proxy statement includes the presentation and discussion of pro forma financial information that incorporates the results of CMS

prepared in accordance with the requirements of Article 11 of Regulation S-X. The proxy statement also includes the presentation and

discussion of Pro Forma Adjusted EBITDA and Pro Forma Adjusted EBITDA Margin, which are not measures of financial performance

under Generally Accepted Accounting Principles in the United States (“GAAP”). Non-GAAP financial measures should be considered in

addition to, but not as a substitute for, the information provided in accordance with GAAP. Management believes that these non-GAAP

measures provide another measure of Amentum’s results of operations and financial condition, including its ability to comply with financial

covenants. See Unaudited Non-GAAP Financial Measures in Appendix A for more information and a reconciliation of our selected reported

results to these non-GAAP measures.

Our Board of Directors

Each of our directors is elected by our stockholders on an annual basis to serve until the next annual meeting

and until their respective successors are elected. Each of our current directors has been nominated for election

to the Board, and you can find additional information regarding our Board nominees under "Proposal 1: Election

of Directors" beginning on page 7.

1 Executive Chair

2 Chief Executive Officer

3 Lead Independent Director

Current Board Composition and Diversity

Corporate Governance Highlights

•Eleven of our thirteen directors are independent.

•The Audit, Compensation, and Nominating and Governance Committees are composed entirely of

independent directors.

•We have a diverse Board of Directors in terms of experience, skills, gender, and ethnicity; 31% of our

Board of Directors is gender and/or racially diverse.

•Our directors serve one-year terms and stand for election annually.

•We provide for a majority voting standard in our bylaws for the election of directors in uncontested

elections and a plurality voting standard for the election of directors in contested elections.

•We do not have a "poison pill" in effect.

•The Board of Directors intends to hold regular executive sessions of independent directors.

•We intend to conduct annual Board and committee evaluations and self-assessments.

•Our policy on public company board service helps to ensure a director's ability to devote necessary time

to Board duties.

•Our Board of Directors and senior leadership exercise oversight in respect of corporate-wide matters,

including enterprise risk management and sustainability.

•The Board of Directors intends to conduct an annual discussion on management succession planning,

with support provided by the Nominating and Governance Committee.

•We adhere to robust executive officer and director stock ownership guidelines.

•Our policies prohibit short sales, frequent trading, and derivative transactions in our equity, as well as

hedging, pledging and the use of margin accounts.

•Our policies include a provision for the recoupment from executives of equity-based compensation in

the event of misconduct leading to a financial restatement.

•Our Investor Relations team and management regularly engage with current and potential stockholders.

Executive Compensation Highlights

•We foster alignment between pay and performance (both company success and shareholder value).

•We emphasize variable pay (short- and long-term incentives) over fixed pay (salary).

•We emphasize long-term versus short-term pay.

•We require our executives and directors to satisfy meaningful stock ownership requirements.

•We ensure an appropriate peer group to benchmark executive compensation.

•We review on a regular basis our executive talent, performance, deployments, and succession.

•We evaluate policies and programs on a regular basis to ensure competitiveness and alignment to

organizational goals.

•We limit excessive compensation for executives by setting compensation caps and restricting excessive

perks and non-monetary benefits.

Additional details about our executive compensation philosophy and structure can be found in the

Compensation Discussion and Analysis ("CD&A"), starting on page 39.

Environmental, Social, and Governance Discussion and Highlights

Our approach to Environmental, Social, and Governance ("ESG") takes the core elements of our corporate

values and instills them into our business strategy with the purpose of challenging convention and driving

progress to bring solutions to the most significant challenges in science, security and sustainability. Doing so

provides an advantage that benefits our shareholders, employees, customers, and the communities where we

live and serve.

ESG Governance

To advance our initiatives around ESG, we have devised a plan of governance through the Nominating and

Governance Committee of our Board having oversight of the Company’s ESG strategy. To facilitate the strategy,

Amentum established an ESG Lead to delineate clear pathways around the Company’s related efforts. With

support and backing from cross-functional leaders around the enterprise, each holding operational or policy-

level responsibility for an area of performance that relates to our ESG priorities, the ESG Lead serves as an

advisory body to our Executive Leadership Team on ESG and sustainability matters.

ESG Commitments and ESG Reporting

•Prior to the Transaction, Amentum committed to near-term targets and net-zero greenhouse gas

emissions by no later than 2040. We plan to reassess these targets including through the Science

Based Targets initiative (SBTi), which provides a window of time to develop science-based target(s) and

become validated by the SBTi.

•We plan to release our 2024 ESG Report in the first half of 2025. The 2024 ESG report will reflect pre-

Transaction ESG actions and will include information from both the Legacy Amentum and CMS

businesses. Our next step will be to issue our ESG report in 2026 to reflect post-closing operations as a

public company, adhering to regulations and following guidelines and reporting frameworks applicable

to our Company and industry.

ESG Awards & Recognitions

Our fiscal year 2024 ESG accomplishments will be outlined in our 2024 ESG Report. Below are select recent

award designations and accolades Amentum is honored to have received:

•2024 Britain's Energy Coast Business Cluster (BECBC) Social Value Award

•2024 National Veteran Small Business Coalition (NVSBC) Champions of Veterans Award

•2024 Global Impact Innovation Award: International Stability Operations Association

•2024 America's Greatest Workplaces: Newsweek

•2024 Top Military Spouse Employer: Military.com Veteran Employment Project

•2024 America's Greatest Workplaces for LGBTQ+: Newsweek

•2023-24 Top 100 Production & Service Suppliers: Intel Corporation

•Sustainable Climate-Ready Award: DOE Office of Sustainable Environmental Stewardship

•U.S. Green Building Council Member

•2024 #11 Top Corporate Diversity Index: Washington Business Journal

•2024 America's Greatest Workplaces for Mental Wellbeing: Newsweek

•2024 America's Greatest Workplaces for Job Starters: Newsweek

•2024 America's Greatest Workplaces for Women: Newsweek

•2024 America's Greatest Workplaces for Diversity: Newsweek

•2024 #7 Top Government Technology Contractors: Washington Business Journal

•2024 VETS Indexes 4 Star Employer: VETS Indexes Employer Awards

•2024 Top Veteran Employer: Military.com Veteran Employment Project

•2023 Engineering News Record Global Awards: #2 Environmental Firm: Federal Market

•2023 Engineering News Record Global Awards: #3 Environmental Firm: Nuclear Waste

•2023 Engineering News Record Global Awards: Top 10 Environmental Firms

•2023 America’s Greatest Workplaces for Parents & Families: Newsweek

•2023 Military Friendly: #1 Employer

•2023 Military Friendly: #1 Supplier Diversity

•2023 Military Friendly: Top 10 Spouse Employer

•2023 US Veterans Magazine Best of the Best: Top Veteran-Friendly Companies

•2023 US Veterans Magazine Best of the Best: Top Supplier Diversity Programs

Human Capital Management

Our team of experienced senior executives leads Amentum with a history of developing, engineering and

delivering complex technical and management solutions to our U.S. federal government customers and allied

governments worldwide. With significant experience in relevant industries or roles, this team is respected by

customers, business partners and employees for their technical expertise across the defense, security,

intelligence, energy and environmental markets. Recognized for their ethical behavior, focus on employee

safety, commitment to inclusion and collaboration, and personal embrace of Amentum’s core values, they lead

by example in support of their leadership brand.

Our team is focused on delivering purpose-driven solutions. We hold ourselves accountable to our team,

customers, company, and communities and innovate as a team passionate about making a difference in an

ever-changing world. Our culture and values embrace inclusion and collaboration, which serve as a beacon for

sharing our continued story of success and experience to all our customers’ missions.

We have created a values-driven culture by fostering a sense of belonging, welcoming all perspectives and

contributions, and providing equal access to opportunities and resources for everyone. Our high-performing

culture supports a best-in-class employee experience devoted to growing a diverse, equitable, and inclusive

workforce. Through our employee resource networks, we aim to tangibly foster community and inclusion in our

workforce. In combination, our ethics and compliance program, high-performing culture, and core values

framework provide our workforce with clarity on what is expected to be successful as an Amentum employee.

As of the closing of the Transaction on September 27, 2024, Amentum had over 53,000 employees, which

excludes employees of our joint ventures. These personnel are assigned in all 50 U.S. states and approximately

80 other countries.

A significant portion of Amentum’s workforce is made up of veterans who served in our nation’s armed forces,

and many of our U.S. employees have a security clearance.