In September 2024, Amentum completed a merger with Jacobs Solutions’ Critical Mission Solutions (CMS) and Cyber & Intelligence (C&I) Businesses, where the combined organization became a publicly traded company.[i] Amentum is involved in the management and operations of U.S. nuclear weapon production facilities, and provides technical and other support for UK nuclear armed submarines.

[i] Amentum Completes Transformational Combination with Jacobs’ Critical Mission Solutions and Cyber and Intelligence Units. Amentum, 27 September 2024. Available at: Amentum Completes Transformational Combination with Jacobs’ Critical Mission Solutions and Cyber and Intelligence Units | Amentum.

Company Profile

Amentum is a U.S. government and commercial services company that spun off from AECOM in 2020.[i] When launched as an independent company in 2020, Amentum became privately held, with the equity firms American Securities and Lindsay Goldberg as equal partners.^[ii] However, in September 2024, Amentum completed a merger with Jacobs Solutions’ Critical Mission Solutions (CMS) and Cyber & Intelligence (C&I) Businesses, where the combined organization became a publicly traded company.[iii] Amentum is involved in the management and operations of U.S. nuclear weapon production facilities, and provides technical and other support for UK nuclear armed submarines. For the fiscal year ending 3 October 2025, Amentum reported revenues of $14.4 billion.[iv]

[i] Amentum Launches as Independent Professional and Technical Services Company Serving the U.S. Federal Government, Select Allied Governments, and Commercial Markets, Amentum, 4 February 2020. Available at: https://www.amentum.com/2020/02/04/amentum-launches-as-independent-professional-and-technical-services-company-serving-the-u-s-federal-government-select-allied-governments-and-commercial-markets/.

^[ii] Amentum Launches as Independent Professional and Technical Services Company Serving the U.S. Federal Government, Select Allied Governments, and Commercial Markets. Amentum, 4 February 2020. Available at: https://www.amentum.com/2020/02/04/amentum-launches-as-independent-professional-and-technical-services-company-serving-the-u-s-federal-government-select-allied-governments-and-commercial-markets//.

[iii] Amentum Completes Transformational Combination with Jacobs’ Critical Mission Solutions and Cyber and Intelligence Units. Amentum, 27 September 2024. Available at: Amentum Completes Transformational Combination with Jacobs’ Critical Mission Solutions and Cyber and Intelligence Units | Amentum.

[iv] ‘ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. For the fiscal year ended October 3, 2025’, Amentum Holdings Inc. (2025), p. 45. Available at: FY25 10-K – 10.03.25.

Contact information

Amentum Holdings, Inc.

4800 Westfields Blvd
Chantilly, VA 20151

United States

Website: Amentum | Global Government & Private-Sector Critical Solutions

LinkedIn: Amentum | LinkedIn

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Nuclear weapons

Since 2024, Amentum is part of the Mission Support and Test Services (MSTS)[1] consortium that manages and operates the Nevada National Security Site (NNSS).[i] The site is used for tests that “provide data relevant to improving our predictive capability, assessing the current stockpile and certifying the future stockpile.”[ii] MSTS is also contracted for producing nuclear weapon “components (particularly pit production)” as well as “strategic materials capabilities”.[iii] The consortium was awarded a 10-year contract in 2017, potentially valued at $11.3 billion.[iv]

Amentum is also part of the team managing and operating the Lawrence Livermore National Laboratory, the lead design agency for the life extension program for the W80-4 cruise missile (Long Range Standoff Weapon) warhead and the modification program for the W87-1 Sentinel warhead.[v] Amentum has also performed readiness assessments at the Los Alamos National Laboratory, responsible for the nuclear design and engineering and life extension programmes for U.S. nuclear warheads.[vi] The contract was originally awarded in May 2007, and currently runs until at least September 2031, with a potential value of $93.3 billion.^[vii]

Amentum works “across all the key sites that enable the UK’s continuous-at-sea deterrent (CASD) program”, including “HMNB Clyde, home base for the Royal Navy’s operational submarines; HMNB Devonport, the largest naval base in Western Europe, BAE Systems Maritime in Barrow-in-Furness, where the Royal Navy’s submarines are built, at Rolls-Royce Nuclear in Derby, where submarine reactors are manufactured, and the Atomic Weapons Establishment in Berkshire, which is responsible for nuclear warhead design and manufacturing.”[viii] Amentum also provides “essential through-life technical support” for nuclear reactors for UK submarines, including the nuclear armed Vanguard and future Dreadnought class submarines.[i]

[i] Project: Naval Nuclear Propulsion (no date) | Amentum. Available at: Naval Nuclear Propulsion | Amentum(Accessed: 20 August 2025).

[1] MSTS is a limited liability company consisting of Honeywell International, Amentum, and HII Nuclear, a subsidiary of Huntington Ingalls Industries (HII).

[i] United States Securities and Exchange Commission, Amendment No. 4 to FORM 10. Amazon Holdco Inc., 13 September 2024, Exhibit 21.1: ‘Expected Subsidiaries of SpinCo Immediately Following the Separation’. Available at: EX-21.1 as included under 10-12B/A.

[ii] ‘FY 2023 - DOE/NNSA Strategic Performance Evaluation and Measurement Plan (PEMP)’, Energy.gov (2022), p. 6. Available at: https://www.energy.gov/nnsa/articles/fy2023-strategic-performance-evaluation-and-measurement-plan-mission-support-test.

[iii] Ibid.

[iv] CONTRACT to MISSION SUPPORT AND TEST SERVICES LLC | USAspending, 1 August 2017. Available at: CONTRACT to MISSION SUPPORT AND TEST SERVICES LLC | USAspending (Accessed: 7 April 2026).

[v] Team (no date) | Lawrence Livermore National Security, LLC Available at: https://www.llnsllc.com/#team (Accessed: 20 August 2025); ‘Fiscal Year 2024 Stockpile Stewardship and Management Plan’, National Nuclear Security Administration (2023), pp. F-6 - F-7. Available at: FY24SSMP_FINAL_NOVEMBER_2023_0.pdf (energy.gov).

[vi] Supporting Our Nation’s Weapons Defense System with Advanced Conduct of Operations and Best-in-Class Operational Readiness at Los Alamos National Laboratory (LANL). Amentum, 1 April 2020. Available at: https://www.amentum.com/project/supporting-our-nations-weapons-defense-system-with-advanced-conduct-of-operations-at-los-alamos-national-labs/; ‘Fiscal Year 2024 Stockpile Stewardship and Management Plan’, National Nuclear Security Administration (2023), pp. F-15 – F16 and F-6 – F7. Available at: FY24SSMP_FINAL_NOVEMBER_2023_0.pdf (energy.gov).

^[vii] CONTRACT to LAWRENCE LIVERMORE NATIONAL SECURITY LIMITED LIABILITY COMPANY.| USAspending, 9 May 2007. Available at: https://www.usaspending.gov/award/CONT_AWD_DEAC5207NA27344_8900_-NONE-_-NONE- (Accessed: 25 August 2025).

[viii] Project: Naval Engineering and Sustainment (no date) | Amentum. Available at: Naval Engineering and Sustainment | Amentum (Accessed: 20 August 2025).

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Last updated: 2026-06-08 14:19:30

Nuclear weapons

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