Amentum Holdings
U.S. defense contractor
From Wikipedia, the free encyclopedia
Amentum Holdings, Inc. (formally Amentum Government Services Holding LLC) is an American government and commercial services contractor based in Chantilly, Virginia.[6][7] The company was formed in 2020 from the spinout of AECOM's Management Services / federal group.[8] After Leidos, it is the second-largest government services (non-equipment producing) contractor in the US government contracting market.[9]
- AECOM Management Services group
- DynCorp
- PAE
- Jacobs Solutions
- Sverdrup & Parcel
 | |
Company type | Public |
|---|---|
| Industry | National security, defense, healthcare, engineering |
| Predecessor |
|
| Founded | February 4, 2020 in Germantown, Maryland |
| Headquarters | Chantilly, Virginia, U.S. |
Area served | Worldwide |
Key people | John Heller (CEO)[1] |
| Products | Government services |
| Revenue |  US$14.4 billion (2025) |
| US$480 million (2025) | |
| US$66 million (2025) | |
| Owner | |
Number of employees | > 53,000 (2025) |
| Website | amentum.com |
| Footnotes / references [2][3][4][5] | |
History
Amentum was founded in 2020 as a spinout of the Management Services Group of AECOM, consisting of the non-construction parts of the company's federal work as well as its commercial operations and maintenance business. This came as a result of a process by AECOM to realign its business to focus more clearly on the architect, engineering, and construction markets.[10]
In March 2024, Amentum announced the completion of its merger with Jacobs Solutions's Critical Mission Solutions and Cyber and Intelligence businesses.[11] In September 2024, it became a publicly traded company on the NYSE under the ticker symbol "AMTM", becoming a part of the S&P 500.[12]
On April 23, 2025, Lockheed Martin announced it had agreed to buy Amentum's Rapid Business Solutions Business for $360 million.[13][14] The deal was closed in June 2025.[15]
As of 2025, the company reported revenue of approximately $14.4 billion and a total backlog of $47.1 billion, with around 50,000 employees operating in more than 70 countries.[16] Amentum operates through two primary business segments: digital services and global engineering.[17][18]
Growth through acquisitions
As part of the strategy by its owners, Amentum has pursued acquisitions of other government contractors including:
Operations
Amentum provides engineering, logistics, and technical services primarily to U.S. government agencies and allied partners. Its work includes defense support services, nuclear security and environmental remediation, space operations,[22] and intelligence and cybersecurity.
The company operates through two msegments: digital services, which includes intelligence analysis, cybersecurity, and space systems support; and global engineering, which includes nuclear remediation, infrastructure engineering, and sustainment services.[17][23]
Major programs and contracts
Space operations
Amentum is the main contractor for NASA's Exploration Ground Systems program at Kennedy Space Center under the Consolidated Operations, Management, Engineering and Test (COMET) contract. The program supports launch infrastructure, vehicle integration, and ground systems for missions within the Artemis program. The company supported integration and launch operations for Artemis I in 2022 and has continued work on Artemis II, including ground systems testing and launch preparation.[24][25]
Nuclear and environmental remediation
Amentum is involved in environmental cleanup and nuclear waste management at multiple U.S. Department of Energy sites. At the Hanford Site in Washington state, the company participates in the Washington River Protection Solutions joint venture managing radioactive tank waste, including treatment and preparation of waste for vitrification.[26][27]
At the Oak Ridge Reservation in Tennessee, Amentum leads United Cleanup Oak Ridge LLC (UCOR), a joint venture with Jacobs and Honeywell that holds the Department of Energy's environmental cleanup contract for the site. The 10-year contract, awarded in 2021 with an estimated ceiling of approximately $8.3 billion, covers cleanup and remedial actions at the East Tennessee Technology Park, cleanup of excess facilities at Oak Ridge National Laboratory and the Y-12 National Security Complex, and the design, construction, and operation of the Environmental Management Disposal Facility. The cleanup work has supported reindustrialization and economic redevelopment of the former Oak Ridge Gaseous Diffusion Plant site.[28] In 2025, Amentum announced a Nuclear Center of Excellence in Oak Ridge to serve as a hub for its nuclear engineering work.[29]
Amentum previously held a contract to operate the Waste Isolation Pilot Plant in New Mexico until 2023, when operations were given to a different contractor.[30]
International nuclear programs
In the United Kingdom, Amentum provides program and project management services for new nuclear energy construction, including work at Hinkley Point C and Sizewell C, where the company serves as the sole programme and project management partner.[31] Amentum also provides engineering support at Sellafield, Britain's largest nuclear decommissioning site.[32]
The company has additional history in UK nuclear decommissioning. From 2012 until 2021, Amentum was part of the Cavendish Dounreay Partnership consortium (with Cavendish Nuclear and Jacobs) that served as the parent body organization of Dounreay Site Restoration Ltd, responsible for the cleanup of Britain's former fast reactor research center in Scotland. From 2008 until 2021, Amentum was the majority partner of UK Nuclear Waste Management Ltd, the consortium operating the Low Level Waste Repository in West Cumbria, the UK's national facility for the disposal of low-level radioactive waste. Both entities transitioned to wholly owned subsidiaries of the Nuclear Decommissioning Authority in 2021.[33][34][35]
Amentum has also supported international decommissioning efforts, including a partnership with Tokyo Electric Power Company on cleanup activities at the Fukushima Daiichi Nuclear Power Plant.[36][37]
Defense and training
Amentum provides flight training services for the United States Army Aviation Center of Excellence at Fort Novosel. The company has also participated in the Cooperative Threat Reduction program supporting chemical, biological, radiological, and nuclear threat reduction.[38][39]
Defense sustainment contracts
In September 2025, Amentum was awarded a U.S. Air Force contract with a ceiling value of approximately $995 million to provide maintenance support for the MQ-9 Reaper fleet.[40][41]
US Immigration and Customs Enforcement
Initially brought in as a subcontractor from Acquisition Logistics LLC[42] before taking over some primary responsibilities. They won a $453 million no-bid contract provided by I.C.E. on March 12th, 2026 through September 30th, 2026. Their primary duties include providing housing, medical care, and transportation of detained migrants as a part of the daily operations of the ICE detention facility Camp East Montana in the Fort Bliss and El Paso, Texas area.[43]