Amentum Holdings Inc (NYSE: AMTM) is a government services company that delivers engineering, environmental remediation, nuclear, intelligence, space, and defense solutions primarily to U.S. federal government customers. Revenue is generated through long-term government contracts, spanning cost-reimbursable, fixed-price, and time-and-materials structures, with cost of revenues running at 89.5% of total revenues for the fiscal year ended October 3, 2025. The company operates across U.S. government, international, and commercial markets, with end-market exposure spanning energy and environmental, intelligence, space, defense, and civilian sectors. Amentum was formed through a merger with CMS, which materially increased revenue scale and drove higher SG&A and amortization of intangible assets including backlog and customer relationships in FY2025. Key service areas include environmental remediation at U.S. Department of Energy sites such as Hanford, Savannah River, Oak Ridge, Portsmouth, and the Idaho Cleanup Project, as well as nuclear decommissioning work for the UK Nuclear Decommissioning Authority at Sellafield.

Revenue model

Long-term U.S. federal and international government contracts, including cost-reimbursable and other contract types. Cost of revenues was 89.5% of revenues in FY2025 (year ended October 3, 2025) and 90.5% in FY2024 (year ended September 27, 2024). SG&A was 4.3% of revenues in FY2025. Additional income comes from equity earnings of non-consolidated subsidiaries via equity method investments.

Products and services

Environmental remediation and site revitalization; nuclear non-proliferation and PFAS solutions; nuclear decommissioning and decontamination; research and lab operations; fusion energy and advanced energy technologies; digital modernization and cyber capabilities; engineering and technology solutions for defense, intelligence, and space end-markets; consulting and proprietary technologies across the government acquisition lifecycle including design, operations management, decommissioning, and regeneration.

Customers and end markets

Primary customers are U.S. federal government agencies. Named end-markets include energy and environmental, intelligence, space, defense, and civilian. Specific agency relationships include the U.S. Department of Energy, the Missile Defense Agency, and the UK Nuclear Decommissioning Authority. Contracts are subject to FAR, CAS, Truthful Cost or Pricing Data Act, and DCAA audit oversight.

Value-chain role

Prime contractor and program executor delivering complex, multi-disciplinary government services. Holds long-term contract vehicles and indefinite-delivery indefinite-quantity contracts. Partners with government customers as an integrated solutions provider from design through operations and decommissioning. Also participates as a subcontractor and holds equity method investments in non-consolidated subsidiaries.

Geographic exposure

Operates in the United States across multiple DOE sites including Hanford, Savannah River, Oak Ridge, Portsmouth, and the Idaho Cleanup Project. International operations include the United Kingdom, specifically Sellafield under the UK NDA, and broader European government remediation and consulting work.

Source: SEC 10-K, filed 2025-11-25

Industry: Services-Business Services, NEC