AMTM · Amentum Holdings, Inc. · Investor Relations

Innovative Hub to Deliver Advanced Engineering and Energy Solutions OAK RIDGE, Tenn.--(BUSINESS WIRE)-- Amentum today opened its Global Nuclear headquarters in Oak Ridge, Tennessee. The facility, which houses Amentum’s Nuclear Center of Excellence , now serves as a centralized hub for the company’s international nuclear business operations. Ribbon cutting at Amentum's Global Nuclear HQ. Located at 151 Lafayette Drive in Oak Ridge, the hub employs more than 150 subject-matter experts dedicated to delivering innovative engineering, technology solutions and advanced energy capabilities. The facility anchors Amentum’s deepening footprint in east Tennessee, where the company already serves as the lead partner in United Cleanup Oak Ridge (UCOR), the U.S. Department of Energy’s prime environmental management contractor for the Oak Ridge Reservation. “The opening of our Global Nuclear Headquarters represents a monumental step forward for our business and our industry,” said Mark Whitney, president of Amentum’s Energy & Environment division. “By centralizing our global nuclear operations in Oak Ridge, we are leveraging strong local partnerships to deliver increased energy capacity to meet the electricity demand of the people and businesses across the U.S. This facility empowers our team of experts to deliver next-generation nuclear innovation, and it builds directly upon the strong operational foundation we've established in the region through our Amentum-led UCOR partnership while contributing directly to regional economic growth.” To sustain the industry’s rapidly expanding need for professional and technical labor, Amentum simultaneously launched the Amentum Nuclear Scholars Program. This transformational initiative establishes a synchronized scholarship pipeline between Roane State Community College and the University of Tennessee, Knoxville (UTK). The newly founded partnership is headlined by a five-year investment from Amentum totaling $500,000 towards developing curriculum and scholarships that build the critical talent pipeline for the world’s growing nuclear energy demands. When combined with other Amentum-led STEM sponsorships and donations in the Oak Ridge community, total student support for these two academic institutions exceeds $1 million. “By launching the Amentum Nuclear Scholars Program alongside our new headquarters, we are directly investing in the local student talent who will pioneer the future of advanced energy and infrastructure solutions,” Whitney said. The educational pipeline will launch its first student cohort stateside in late 2026, followed by integration with Amentum’s international academic partners in the fall of 2027. To celebrate the opening, Amentum hosted a ribbon-cutting ceremony featuring CEO John Heller , U.S. Rep. Chuck Fleischmann (R-TN-03) local elected leaders and school officials. “This partnership paves the way for students to gain the educational foundation necessary to excel as future leaders in the nuclear industry,” said UTK Tickle College of Engineering (TCE) Dean Matthew Mench, the Wayne T. Davis dean’s chair of the college. “Through the financial support from Amentum and practical internship experiences, TCE students will be prepared to step directly into high-demand roles that will positively impact our community, state and country.” “By partnering with Amentum, we are opening doors for students to start right here in their community and graduate onto a global stage,” said Dr. Chris Whaley, Roane State Community College president. “The Amentum Nuclear Scholars Program removes the financial hurdles that often halt a student’s momentum, providing a direct, supported pathway from our classrooms straight into high-wage, high-impact careers.” About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our

CHANTILLY, Va.--(BUSINESS WIRE)-- United Kingdom nuclear site operator Sellafield Ltd has selected an Amentum (NYSE: AMTM) joint venture as preferred supplier for an asset care and asset creation program valued at up to $2.78 billion (£2.1 billion). Image courtesy of Sellafield Ltd. Under the Projects and Asset Care Execution (PACE) framework contract, Amentum and its supply chain partners will support Sellafield Ltd’s spent fuel management and retrievals mission by providing full lifecycle capabilities including engineering and design, procurement, installation and plant modification, project management and controls, commissioning, dismantling, removal and ongoing asset care. “Sellafield Ltd has selected us and our trusted suppliers because of our record of excellent delivery performance, collaborative behaviors and constant innovation and improvement, driven by application of technologies such as digital visualization and advanced robotics,” said John Heller, Chief Executive Officer of Amentum. “PACE provides a significant, long-term growth opportunity for Amentum at Sellafield, building on our existing capability and relationships while also enabling us to deliver a broader, integrated full lifecycle scope on higher value projects across engineering and asset care.” "Our mission is to create a clean, safe and secure environment for future generations. To do this we must ensure our assets remain safe, reliable and fit for the future,” said Matthew Johns, Chief Engineer, Sellafield Ltd. “The PACE agreement is an important step to strengthen our asset care capability. It will provide the expertise we need to maintain a high standard of safe and efficient delivery.” Formal award of the framework agreement will follow when final contractual arrangements are concluded. Lot 1 of PACE will be delivered by OneAxIoM, a joint venture between Amentum and Mitie Plc, supported by key supply chain partners Assystem and Mott MacDonald. The initial contract duration is nine years, with an optional six-year extension. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn About Amentum in the UK With more than 6,000 people in the UK, Amentum is the delivery partner for project and construction management services at Hinkley Point C; sole program and project management delivery partner at Sizewell C; and supports the UK’s existing nuclear power stations under a Lifetime Enterprise Agreement with EDF. It is a major supplier of engineering design, safety case and project management at Sellafield and other UK nuclear decommissioning sites and operates the country’s largest private sector complex of nuclear laboratories and engineering test facilities in Warrington. Forward-Looking Statements This press release contains or incorporates by reference statements by Amentum Holdings, Inc. (the “Company”) that relate to future events and expectations and, as such, constitute “forward-looking statements” as that term is defined in the Private Securities Litigation Reform Act of 1995 and other federal securities laws. These forward-looking statements may be characterized by terminology such as “believe,” “project,” “expect,” “anticipate,” “estimate,” “forecast,” “outlook,” “target,” “endeavor,” “seek,” “predict,” “intend,” “strategy,” “plan,” “may,” “could,” “should,” “will,” “would,” “

Company to Deliver Digital and Cybersecurity Solutions to Boost Grid Resilience CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM), a global leader in advanced engineering and technology solutions, has been selected for strategic positions on two significant UK energy frameworks awarded by Scottish and Southern Electricity Networks (SSEN) Transmission. Amentum will be the exclusive provider of high-end cybersecurity engineering services which aim to digitize and enhance the security of the United Kingdom’s energy grid. Amentum will deliver cybersecurity services to SSEN Transmission to strengthen UK's energy grid SSEN Transmission is the owner and operator of the high voltage electricity transmission system for the north of Scotland, powering the clean energy transition and delivering a reliable, efficient network that creates lasting benefits for communities, the economy and the environment. “SSEN Transmission is expanding the grid at a pace the UK's energy security depends on, and that growth must be secure by design,” said Matthew Morgan, UK-based group director for Security, Systems and Integration at Amentum. “Our teams will protect critical assets, scale digital capability, and turn operational data into faster, better decisions. We are investing in our team in Scotland to deliver this work, backed by Amentum's deep UK and international experience.” Working from offices in Cardiff, Glasgow, London, and Warrington, Amentum will build upon existing security architecture work the company has performed for SSEN Transmission since 2022. Under three-year agreements, Amentum will leverage its expertise in digital transformation, operational technology (OT), and renewable energy integration to support the UK’s energy transition goals. “The Five Eyes cyber security agencies have recognized the impact of AI in accelerating the speed, scale and sophistication of cyber threats. Leveraging Amentum’s proven expertise in modernizing and securing critical digital infrastructure, we can support SSEN Transmission in addressing one of the most serious challenges of our time,” said Jennifer Walsmith, president of Intelligence & Cyber at Amentum. “We look forward to delivering the innovation and security needed to strengthen the UK’s energy future.” About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. About Amentum in the United Kingdom With more than 6,000 people in the UK, Amentum is the delivery partner for project and construction management services at Hinkley Point C; sole program and project management delivery partner at Sizewell C; and also supports the UK’s existing nuclear power stations under a Lifetime Enterprise Agreement with EDF. It is a major supplier of engineering design, safety case and project management at Sellafield and other UK nuclear decommissioning sites and operates the country’s largest private sector complex of nuclear laboratories and engineering test facilities in Warrington. In the defence sector, Amentum has an essential role in the UK’s continuous at-sea deterrent by providing safety advice and technology services for the Royal Navy’s nuclear submarines and program management and engineering support for AWE. Amentum’s specialist teams also assist procurement and operational delivery of goods and services across the whole of the UK Ministry of Defence. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Am

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM) has been awarded the Center Maintenance, Operations, and Engineering II (CMOE II) contract at NASA Langley Research Center in Hampton, Virginia, a renowned hub for scientific discovery and innovation. The award reaffirms Amentum’s role as a trusted partner in advancing NASA’s groundbreaking research, technology development, and exploration goals. Image credit: NASA Langley / David C. Bowman “The scope of solutions and capabilities we deliver will ensure NASA Langley sustains its critical role in advancing space science and deep space exploration. Amentum’s technical expertise and agile management strategies have been instrumental in supporting NASA’s vision for solving critical challenges and driving future innovation,” said Mark Walter, president of Amentum’s Engineering and Technology business. Under the CMOE II contract, Amentum will deliver cutting-edge support for advanced research systems such as wind tunnels, laboratories, and research utilities. Amentum will also provide advanced engineering expertise including design, project, construction, and configuration management, and pressure system recertification. Finally, Amentum will deliver vital mission capabilities, including preventive maintenance, repairs, and central utilities operations across NASA Langley’s institutional and research facilities. Amentum has been a dedicated partner to NASA for over six decades, consistently delivering innovative, safe, and sustainable solutions to meet the agency’s evolving needs. Through this new contract, the company will continue to play a key role in advancing Langley’s success by managing complex systems, optimizing operational processes, and spearheading critical capital improvements. These efforts include modernizing NASA Langley’s infrastructure, including automating laboratory systems and wind tunnel testing facilities. The CMOE II award reinforces Amentum’s commitment to maintaining the reliability and excellence of NASA Langley’s world-class facilities. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn Forward-Looking Statements This press release contains or incorporates by reference statements by Amentum Holdings, Inc. (the “Company”) that relate to future events and expectations and, as such, constitute “forward-looking statements” as that term is defined in the Private Securities Litigation Reform Act of 1995 and other federal securities laws. These forward-looking statements may be characterized by terminology such as “believe,” “project,” “expect,” “anticipate,” “estimate,” “forecast,” “outlook,” “target,” “endeavor,” “seek,” “predict,” “intend,” “strategy,” “plan,” “may,” “could,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” or the negative thereof or variations thereon or similar terminology generally intended to identify forward-looking statements. All statements, other than historical facts, including, but not limited to, statements regarding the anticipated work and revenue under the awarded contract, and the Company’s objectives, expectations and intentions, applicable legal, economic and regulatory conditions, and any assumptions underlying any of the foregoing, are forward-looking statements. A number of important factors could cause actual results to

Award from Babcock enables support across nuclear, marine, land and aviation domains CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM) has joined a five-year Babcock International Group Engineering Services Framework to support nuclear, marine, land, aviation and mission systems for the UK Armed Forces at home and abroad. Image courtesy of Babcock International Group The agreement forms part of a wider strategy to build closer, long-term partnerships with key suppliers, creating a simpler and more consistent way to bring specialist engineering expertise into critical defence programmes. The framework enables suppliers to support multiple projects more quickly, helping streamline procurement and strengthen collaboration. The award of the framework builds on decades of infrastructure support to Babcock’s Devonport Royal Dockyard, His Majesty’s Naval Base Clyde, and the Rosyth Royal dockyard, and enables on-going and future support to critical UK defence and submarine programmes, as well as broader support for platforms and infrastructure across the nuclear, marine, land, and air domains. “Our decades of naval nuclear infrastructure experience, the breadth and depth of our engineering and architectural skills, together with our unrivalled scientific reach back, makes Amentum a one-stop shop for Babcock’s engineering, nuclear and technical requirements,” said Loren Jones, senior vice president and head of Amentum’s Energy & Environment-International business. “We are looking forward to supporting the delivery of programmes vital to the UK’s safety and security in the years ahead, deploying our proven experience of modernizing the UK’s naval bases, dockyards and defence systems, including specialized technical validation for critical infrastructure such as docks, berths and shiplifts for the maintenance of Astute and Dreadnought-class submarines, and for the wider Royal Navy fleet.” Amentum provides complex programme, project and engineering solutions, including: requirements management; architectural design and building services; multi-disciplinary design engineering (marine, civil / structural, electrical, control and instrumentation and mechanical); and specialist technical support, such as safety case authoring, Human Factors, 3D Building Information Modelling, geotechnical studies, seismic / blast assessment and Independent Technical Assessment. Amentum also supports critical defence programmes more widely, providing research and technology services, safety case, and security services for the Royal Navy’s nuclear propulsion systems. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. About Amentum in the United Kingdom With more than 6,000 people in the UK, Amentum is the delivery partner for project and construction management services at Hinkley Point C; sole programme and project management delivery partner at Sizewell C; and also supports the UK’s existing nuclear power stations under a Lifetime Enterprise Agreement with EDF. It is a major supplier of engineering design, safety case and project management at Sellafield and other UK nuclear decommissioning sites and operates the country’s largest private sector complex of nuclear laboratories and engineering test facilities in Warrington. In the defence sector, Amentum has an essential role in the UK’s continuous at-sea deterrent by providing safety advice and technology services for the Royal Navy’s nuclear submarines

CHANTILLY, Va.--(BUSINESS WIRE)-- Australian Naval Infrastructure (ANI) selected a joint venture between Amentum (NYSE: AMTM) and Laing O’Rourke as its Capability Partner to support the delivery of a nuclear-powered submarine construction yard in South Australia. Osborne Naval Shipyard, South Australia Under a long-term contract, Amentum and Laing O’Rourke will play a central role in developing the new shipyard at Osborne, north of Adelaide, where Australia’s nuclear-powered submarines will be built as part of the AUKUS trilateral agreement. “Amentum has the opportunity to be part of a once-in-a-generation national endeavor that will shape Australia’s sovereign nuclear capability for decades,” said Mark Whitney, president of Amentum Energy & Environment. “We bring more than 60 years of global expertise in nuclear submarine programs, significant nuclear licensee experience, independent regulator exposure and a clear pathway for growing enduring Australian nuclear capability.” “Our team will provide hands-on leadership across key areas of delivery, including governance, assurance, logistics, commissioning, digital engineering, supply chain quality, and integrating construction expertise into the design phase,” said Kim Katheklakis, Amentum Australia managing director. The Capability Partner will provide nuclear-related program management, construction management and safety leadership within ANI’s Integrated Delivery Office. The partnership will collaborate closely with ANI to coordinate work packages, support contractor engagement and ensure seamless interface management across the nuclear and non-nuclear areas of the submarine construction yard. The new construction yard will enable Australia to build and sustain conventionally armed, nuclear‑powered submarines for the first time. It will house the advanced facilities required for assembly, outfitting, testing and commissioning of the future SSN‑AUKUS fleet. This project is critical to strengthening Australia’s long‑term national security, deepening defense industrial capability, and creating thousands of highly skilled jobs in South Australia. As part of the AUKUS partnership with the United States and United Kingdom, the program will position Australia as a key contributor to stability in the Indo‑Pacific region. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. In Australia, Amentum has more than 1,000 team members delivering engineering, program and project management services to government and commercial clients in a range of sectors including defense and national security, cyber and digital, energy and environment, and critical infrastructure. With the AUKUS program accelerating, we are growing our team and capabilities to support the establishment of sovereign nuclear capability in Australia – from the construction of nuclear-licensed facilities and nuclear-powered submarines to through-life operations, decommissioning, disposal, cleanup, and radioactive waste management. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn Forward-Looking Statements This press release contains or incorporates by reference statements by Amentum Holdings, Inc. (the “Company”) that relate to future events and expectations and, as such, constitute “forward-looking statements” as that term is defined in the Private Securities Litigation Reform Act of 1995 and other federal securities laws. These forward-looking statements may be characterized by terminology such as “believe,” “project,” “expect,” “anticipate,” “estimate,” “forecast,” “outlook,” “target,” “endeavor,” “seek,” “predict,” “intend,” “strategy,” “

Revenues of $3.5 billion Net Income of $66 million; Adjusted EBITDA of $290 million Diluted Earnings Per Share of $0.27; Adjusted Diluted Earnings Per Share of $0.67 Operating Cash Flow of $146 million; Free Cash Flow of $135 million Backlog of $48.2 billion ; Book-to-Bill of 1.1x, Last Twelve Months 1.3x CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum Holdings, Inc. (“Amentum” or the “Company”) (NYSE: AMTM), a leading advanced engineering and technology company, today announced results for the third quarter ended July 3, 2026. “We delivered solid third quarter results with strong operating performance, profitability, and free cash flow," said Amentum Chief Executive Officer John Heller. “Although near-term dynamics have impacted our revenue outlook, our strong year-to-date results allow us to increase guidance for both Adjusted EBITDA and Adjusted Diluted EPS. Looking ahead, we’ve made significant progress executing our strategy and our leading business development indicators remain robust including recently announced key wins and partnerships in global nuclear energy. We remain focused on delivering differentiated solutions to our customers and driving long-term value for our shareholders.” Summary Operating Results Three Months Ended (in millions, except per share data) July 3, 2026 June 27, 2025 % Change GAAP Measures: Revenues $3,490 $3,561 (2%) Operating income $172 $103 67% Net income $66 $10 560% Diluted earnings per share $0.27 $0.04 575% Non-GAAP Measures 1 : Adjusted EBITDA 1 $290 $274 6% Adjusted EBITDA Margin 1 8.3% 7.7% +60 bps Adjusted Diluted Earnings Per Share (EPS) 1 $0.67 $0.56 20% Free Cash Flow 1 $135 $100 35% 1 – 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 at the end of this press release for more information and a reconciliation of our selected reported results to these non-GAAP measures. GAAP Results Revenues of $3,490 million decreased 2% year-over-year driven by a 3% impact from the transition of certain contracts from consolidated to unconsolidated joint ventures and fiscal year 2025 divestitures; partially offset by the ramp-up of new contract awards in critical digital infrastructure and space systems and technologies. Operating income increased as a result of strong operational performance and decreased intangible amortization expense. Net income and diluted earnings per share improved year-over-year, supported by higher operating income and lower interest expense. Non-GAAP Results Adjusted EBITDA of $290 million resulted in Adjusted EBITDA Margins of 8.3%, up from 7.7% in the prior year quarter, driven by continued progress on our margin expansion initiatives including a favorable mix shift and strong operational performance. Adjusted Net Income and Adjusted Diluted Earnings Per Share increased primarily as a result of the strong operational performance and lower interest expense. Non-GAAP Segment Results Three Months Ended (in millions) July 3, 2026 June 27, 2025 % Change Revenues Digital Solutions $1,457 $1,421 3% Global Engineering Solutions 2,033 2,140 (5%) Total Revenues $3,490 $3,561 (2%) Adjusted EBITDA 1 Digital Solutions $116 $114 2% Global Engineering Solutions 174 160 9% Total Adjusted EBITDA $290 $274 6% 1 – 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 at the end of this press release for more information and a reconciliation of our

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM) has been selected by the U.S. Department of Energy’s National Nuclear Security Administration (NNSA) to enter negotiations for a phased lease to develop one of the nation’s largest integrated artificial intelligence and energy infrastructure projects at the Savannah River Site (SRS) in South Carolina. Once finalized, the public-private project would establish a 1-gigawatt artificial intelligence data center supported by approximately 2 gigawatts of on-site energy generation, initially powered by natural gas bridging to advanced nuclear energy. data center stock footage “Artificial intelligence, energy resilience, and national security are becoming increasingly interconnected, creating new opportunities to strengthen America’s strategic advantage,” said John Heller, Chief Executive Officer of Amentum. “Amentum is uniquely positioned at that intersection, combining deep engineering expertise, trusted mission execution, and decades of partnership with the U.S. government. This agreement gives us the opportunity to partner with the NNSA to deliver infrastructure that will help power the technologies shaping our nation’s future.” Artificial intelligence is transforming the way governments, industries and societies operate – and its continued advancement depends on resilient, secure energy infrastructure capable of powering the next generation of computing. “For generations, Amentum has helped solve some of the nation’s most complex engineering and nuclear challenges, including at the Savannah River Site,” said Mark Whitney, president of Amentum’s Energy & Environment business. “This opportunity builds on that legacy by bringing together our expertise in nuclear operations, infrastructure development, and program delivery to help our customer safely and securely accelerate the next generation of AI and energy infrastructure.” The SRS data center project is designed to accelerate domestic AI computing capacity, expand reliable power generation, and demonstrate how public-private partnerships can advance innovative technologies while strengthening America’s critical infrastructure. As demand for advanced technologies continues to grow, Amentum remains committed to delivering the engineering excellence, trusted partnerships, and mission-focused innovation that help customers strengthen national security, enhance energy resilience, and build the critical infrastructure that will define the future. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all seven continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn Forward-Looking Statements This press release contains or incorporates by reference statements by Amentum Holdings, Inc. (the “Company”) that relate to future events and expectations and, as such, constitute “forward-looking statements” as that term is defined in the Private Securities Litigation Reform Act of 1995 and other federal securities laws. These forward-looking statements may be characterized by terminology such as “believe,” “project,” “expect,” “anticipate,” “estimate,” “forecast,” “outlook,” “target,” “endeavor,” “seek,” “predict,” “intend,” “strategy,” “plan,” “may,” “could,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” or the negative thereof or variations thereon or similar terminology generally intended to iden

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM), a global leader in advanced engineering and innovative technology solutions, will host a conference call on August 11, 2026, at 8:30 AM EDT to discuss financial results for the third quarter fiscal year 2026 ending July 3, 2026. A news release containing the results will be issued prior to the call. Amentum Q3 FY26 Earnings Call 8:30am August 11 The conference call will be webcast to the public through a link on Amentum’s Investor Relations Website . A replay of the conference call, along with the earnings press release, presentation slides and supplemental financial disclosures, will be available via the same link . About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn Media Contact: Chanel Mann [email protected] Investor Contact: Joseph DeNardi [email protected] Source: Amentum

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM), a global advanced engineering and technology company, has been named to the list of America’s Best Companies 2026 by TIME Magazine. America’s Best Companies, an annual ranking by TIME magazine in partnership with Statista, identifies top-performing U.S. companies using a data-driven evaluation across employee satisfaction, financial strength, and sustainability transparency. TIME America's Best Companies 2026 in partnership with Statista “Recognition in TIME Magazine’s America’s Best Companies 2026 is an accolade reflecting the tremendous efforts and commitment of our employees, whose talent and dedication make Amentum a leader in solving the world’s science, security and sustainability challenges,” said John Heller, Amentum chief executive officer. "We strive for excellence not just in what we achieve, but also in how we operate—with integrity, purpose, and a focus on impact for our clients and stakeholders.” “This recognition is a direct reflection of our people-first culture and the incredible community we have built at Amentum. We prioritize the needs of our team members because we know they are the foundation of our success,” said Darren Burton, Amentum chief people officer. “This award also highlights our ongoing efforts to create a sustainable future through responsible business practices and thoughtful governance. I want to thank every employee who helped make this award possible – your voice, dedication, and contributions are what truly place Amentum among the best." About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn Forward-Looking Statements This press release contains or incorporates by reference statements by Amentum Holdings, Inc. (the “Company”) that relate to future events and expectations and, as such, constitute “forward-looking statements” as that term is defined in the Private Securities Litigation Reform Act of 1995 and other federal securities laws. These forward-looking statements may be characterized by terminology such as “believe,” “project,” “expect,” “anticipate,” “estimate,” “forecast,” “outlook,” “target,” “endeavor,” “seek,” “predict,” “intend,” “strategy,” “plan,” “may,” “could,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” or the negative thereof or variations thereon or similar terminology generally intended to identify forward-looking statements. All statements, other than historical facts, including, but not limited to, statements regarding the anticipated work and revenue under the awarded contract, and the Company’s objectives, expectations and intentions, applicable legal, economic and regulatory conditions, and any assumptions underlying any of the foregoing, are forward-looking statements. A number of important factors could cause actual results to differ materially from those contained in or implied by these forward-looking statements, including those factors discussed in our filings with the Securities and Exchange Commission (SEC), including, among others: the occurrence of an accident or safety incident; the ability of the Company to control costs, meet performance requirements or contractual schedules; and other factors set forth under Item 1A, Risk Factors in our Annual Report on Form 10-K for the fiscal year ended Se

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM), a global leader in advanced engineering and technology solutions, has been awarded NASA’s Consolidated Spaceflight Mission Operations and Systems (COSMOS) contract. The award comes through the ASCEND Aerospace & Technology, LLC, a joint venture between Amentum and Aerodyne Industries, LLC, formed under the Small Business Administration’s Mentor-Protégé Program. Mission Control Center at NASA’s Johnson Space Center; image courtesy of NASA The COSMOS work reinforces Amentum's vital role in the U.S. space program in support of the NASA mission to explore new frontiers and advance human understanding. “Amentum’s proven track record in enabling complex spaceflight missions makes us an ideal partner to advance U.S. leadership in space,” said Mark Walter, president for the Engineering and Technology business at Amentum. “Through the ASCEND partnership, we’re delivering the space systems and training solutions to facilitate NASA’s ambitious goals for deep-space exploration and scientific discovery.” Under the COSMOS contract, ASCEND will deliver critical mission operations, systems, and training solutions to support NASA’s Flight Operations Directorate at the Johnson Space Center in Houston, Texas. This work will play a vital role in advancing some of NASA’s most complex and high-profile programs, including the Orion and Space Launch System (SLS) programs which enable future deep-space exploration as well as International Space Station (ISS) operations and astronaut training programs. Additional programs include the Commercial Crew Program, which expands access to low-Earth orbit and the Artemis program, aimed ultimately at developing a sustained human presence on the lunar surface. Amentum will provide expertise in Mission Control Center systems, training for both astronauts and instructors, flight controller readiness, training systems development, and mockup environments that replicate real-world conditions, delivering mission-ready solutions as a trusted partner to NASA and the U.S. space enterprise. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow <a href="https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Ftwitter.com%2Famentum_corp&esheet=54562318&newsitemid=20260630998168&lan=en-US&anchor=%40Amentum_corp&index=3&md5=66d96f5e940e2aea353dc1

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM) will deliver logistics operations support under a new 60-month firm-fixed price contract awarded by the General Services Administration (GSA) to provide modernized, end-to-end, AI-powered supply chain solutions for the Pentagon and other federal customers operating across Japan as part of the U.S. Indo-Pacific Command (INDOPACOM) area of responsibility. Amentum will enhance operational readiness in a strategic region by ensuring seamless supply chain management for U.S. military installations. Kadena Air Base, Okinawa Japan “Amentum’s new relationship with the GSA is a natural fit given our unique global supply chain reach, forward-positioned operational capability and expeditionary sustainment,” said Dr. Karl Spinnenweber, president of Amentum’s Mission Solutions business. "Our extensive experience in delivering turnkey supply chain solutions worldwide ensures we can support the GSA and INDOPACOM with predictability, reliability, and efficiency.” Amentum has integrated these capabilities into a single, agile framework to ensure seamless operations in contested, austere and politically sensitive environments. AI tools will be incorporated into the program to enhance demand planning, forecasting and catalog management to improve customer order fulfillment and delivery. Amentum will implement a comprehensive approach to supply chain management, delivering tailored solutions to ensure uninterrupted operational sustainment. The company is leveraging technology solutions to monitor, analyze, and optimize supply chain activities, including demand forecasting, procurement, transportation, inventory management, and on-time delivery. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn Forward-Looking St

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM), a global advanced engineering and technology company, has been named to the Fortune 500 list at the #313 position. The Fortune 500, published annually by Fortune magazine, ranks the largest U.S. corporations based on total revenue for the previous fiscal year. 2026 Fortune 500 “Amentum’s inclusion on the Fortune 500 is a testament to the dedication of our 50,000 employees in more than 70 nations, as well as the enduring and trusted relationships forged with our customers and partners," said John Heller, Amentum chief executive officer. “By delivering innovative, technologically advanced solutions in national security, energy, space, intelligence, and infrastructure, we are addressing today’s challenges and leading these critical industries into the future.” "This milestone in Amentum’s history is about more than financial performance. It demonstrates our commitment to innovation, operational excellence, and problem-solving on a global scale,” said Travis Johnson, Amentum chief financial officer. "As we grow, we remain steadfast in our commitment to delivering innovative advanced engineering and technology solutions to solve the most significant and complex challenges in science, security and sustainability.” About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn Forward-Looking Statements This press release

Visionary AI and Robotics Leader to Drive Scalable Innovation Across Global Markets CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM), a global leader in advanced engineering and technology solutions, has named Dr. Sam Nazari the company’s Chief AI Architect. In this role, Dr. Nazari will drive Amentum-wide AI integration to accelerate innovation and work closely with programs to optimize mission impact for customers across the defense, intelligence, energy, space, and commercial sectors. Sam Nazari, Chief AI Architect, Amentum "Advancements in artificial intelligence are revolutionizing how mission objectives are achieved, enabling unprecedented levels of enterprise efficiency, precision, and scalability, " said Jill Bruning, Amentum chief technology officer. "With Sam’s unique expertise, he will strategically drive results-focused AI solutions that empower our customers to tackle their most complex challenges – ultimately advancing the world’s most critical missions.” In this newly established role, Dr. Nazari’s focus spans both customer-facing AI solutions and internal operational automation. His priorities include aligning AI investments with mission-critical customer demand signals, and ensuring all AI deployments meet FedRAMP, CMMC, and client compliance standards. Dr. Nazari has architected solutions ranging from AI-powered supply chain systems to state-of-the-art autonomous technologies supporting challenging defense environments and tactical operations. Before the Chief AI Architect role, Dr. Nazari worked for Amentum leading key AI initiatives at DARPA. Prior to joining Amentum, he held roles at Scientific System Company, Inc. (SSCI) and Systems & Technology Research (STR), driving AI and machine learning (ML) advancements for the Department of Defense. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow <a href="https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fww

Revenues of $3.5 billion Net Income of $54 million; Adjusted EBITDA of $275 million Diluted Earnings Per Share of $0.22; Adjusted Diluted Earnings Per Share of $0.60 Operating Cash Flow of $225 million; Free Cash Flow of $220 million Backlog of $47.8 billion; Book-to-Bill of 1.2x, Last Twelve Months 1.2x Issued $1.4 Billion Term Loan A; Proceeds Used to Repay and Reprice Term Loan B CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum Holdings, Inc. (“Amentum” or the “Company”) (NYSE: AMTM), a leading advanced engineering and technology company, today announced results for the second quarter ended April 3, 2026, and reaffirmed guidance for its fiscal year 2026. “Amentum delivered another quarter of solid performance across all key financial and business development metrics," said Amentum Chief Executive Officer John Heller. “We see significant and growing opportunities across national security, nuclear energy, space, and critical digital infrastructure markets with most of these in the early stages of a substantial investment cycle. We believe that our strategic alignment with these markets and our focus on execution, innovation, and delivery excellence will translate into long-term value for our shareholders.” Summary Operating Results </p

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM), a global leader in advanced engineering and innovative technology solutions, will host a conference call on May 12, 2026, at 8:30 AM EDT to discuss financial results for the second quarter fiscal year 2026 ending April 3, 2026. A news release containing the results will be issued prior to the call. Amentum FY26 Q2 Earnings The conference call will be webcast to the public through a link on Amentum’s Investor Relations Website . A replay of the conference call, along with the earnings press release, presentation slides and supplemental financial disclosures, will be available via the same link . About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in approximately 80 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow Amentum on LinkedIn Media Contact: Chanel Mann [email protected] Investor Contact: Joseph DeNardi <a href="mailto:IR@amentum

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM), a global leader in advanced engineering and technology solutions, today announced the appointment of Joseph (Joe) DeNardi as Senior Vice President and Head of Investor Relations. DeNardi will lead Amentum’s investor relations strategy, oversee engagement with the investment community, and help drive strategic financial initiatives that support the company’s long-term growth objectives. Joe DeNardi, Amentum Senior Vice President and Head of Investor Relations “Joe DeNardi’s deep understanding of the government services and defense sectors, combined with his experience leading investor relations and corporate finance organizations, positions him well to continue advancing Amentum’s value proposition as a global leader in our market,” said Amentum Chief Financial Officer, Travis Johnson. “We are pleased to welcome Joe to our leadership team as we execute on our long-term growth strategy and expand our relationships with shareholders, analysts, and the broader financial community.” DeNardi previously held senior finance leadership roles at Science Applications International (SAIC), including Head of Corporate FP&A, Investor Relations, and Treasurer. He brings deep experience across investor relations, corporate finance, and capital markets. Prior to SAIC, DeNardi served as a Managing Director in equity research at Stifel Financial, covering the Aerospace & Defense and Government Services sectors. DeNardi holds a bachelor’s degree from The College of William & Mary and a master’s degree in finance from Loyola University Maryland. DeNardi succeeds Nathan Rutledge who left the company to pursue other opportunities. Rutledge previously led Amentum’s investor relations efforts during an important phase of the company’s evolution following Amentum’s merger with Jacobs’ Critical Mission Solutions and Cyber and Intelligence businesses, and the combined company’s subsequent public listing. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X. Follow <a href="https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fwww.link

Team Performs Seamless Launch Preparation and Pad Operations at Kennedy Space Center CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM) provided critical ground systems operations to NASA on the Artemis II mission, the first crewed flight in the Artemis program. The mission marked a new era in human space exploration, advancing NASA’s objective of a sustainable lunar presence and setting the stage for future deep-space exploration and habitation. “Artemis II is a giant leap not just for NASA, but for humanity’s reawakening to human space exploration,” said Mark Walter, president of Amentum’s Engineering & Technology business. “Amentum works at NASA space centers embedding advanced engineering directly into the environments where the nation’s most critical missions are planned, tested, and executed. We are proud to be a trusted partner as NASA takes this historic step forward, combining advanced engineering with operational excellence to enable safe and successful spaceflight.” Amentum’s ground system support to Artemis II covered complex mission critical areas—from driving the iconic Crawler Transporter and integrating the vehicle on the Mobile Launcher, to deploying NASA’s Emergency Escape System and conducting a full Wet Dress Rehearsal. In addition to ground systems development and preparation, Amentum supported precision hypergolic servicing, or management of rocket fuels and oxidizers, meticulous SLS and Orion testing, closeout activities, and comprehensive system validations. Every operation reflected Amentum’s commitment to safety, reliability, and innovation—hallmarks of the company’s partnership in advancing human space exploration. Amentum’s involvement extended beyond launch operations. Pre-launch, Amentum supported NASA by conducting scientific research, design, development, and testing for a number of Artemis program elements. Post-mission, Amentum supported NASA and the U.S. Navy with recovering the Orion spacecraft from the Pacific Ocean near San Diego, ensuring the integrity of the vehicle and the safety of its crew as they return to Earth. The success of Artemis II reaffirms Amentum’s commitment to NASA delivering the engineering innovation, operational excellence, and mission-critical performance required to advance NASA’s long-term goals for sustained lunar exploration and habitation in future deep-space missions. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow <a href="https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fx.com%2Famentum_corp&

CHANTILLY, Va.--(BUSINESS WIRE)-- Amentum (NYSE: AMTM) has been awarded a $425 million contract by the California Department of Forestry and Fire Protection (CAL FIRE) to deliver aerial firefighting support to the state. The initial three-year contract includes two option years. California Department of Forestry and Fire Protection (CAL FIRE) The partnership underscores the company’s commitment to supporting California in its battle against wildfires. “Amentum is uniquely positioned to manage the training, scheduling and mobilization of pilots and mechanics to deliver aviation solutions that protect California’s environment and critical infrastructure,” said Dr. Karl Spinnenweber, president of Amentum’s Mission Solutions business. "Amentum brings advanced technical solutions, including AI-driven predictive maintenance, repair and overhaul services, as well as world-class logistics and deployment expertise to help the state safeguard communities and its economy." Amentum will deliver a full spectrum of aviation expertise, ranging from program management and training to the operational deployment of 350 elite pilots and mechanics. Their mission is to bolster California’s firefighting capabilities in the face of an escalating wildfire crisis, ensuring the state’s fleet of specialized aircraft remains fully operational and ready to deploy. “Today’s fire season is no longer seasonal. It’s a year-round battle that grows more dangerous with each passing year," said Spinnenweber. “With decades of aviation excellence, we are committed to ensuring aircraft and crews are ready at a moment’s notice, both here at home and globally, for the toughest, most vital operations.” About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Visit us at amentum.com to learn how we advance the future together. Follow @Amentum_corp on X Follow <a href="https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fwww.linkedin.com%2Fcompany%2Famentumcorp%2F&esheet=54481185&newsitemid=202604075

CHANTILLY, Va.--(BUSINESS WIRE)-- Great British Energy – Nuclear (GBE-N) has awarded a $406 million (£300 million) contract to a joint venture between Amentum (NYSE: AMTM) and Cavendish Nuclear to serve as the owner’s engineer for the UK’s groundbreaking small modular reactor (SMR) program. Contract signing - left to right: Mick Gornall, Managing Director, Cavendish Nuclear; Loren Jones, Senior Vice President, Amentum; Simon Roddy, Chief Executive Officer, Great British Energy-Nuclear; Kenny Douglas, DevCo Director, Great British Energy-Nuclear This long-term agreement, with a maximum duration of 14 years, will support the deployment of Rolls-Royce SMR’s innovative reactor technology at the Wylfa site in North Wales. The contract represents a significant milestone in advancing the UK’s clean energy ambitions and the rollout of its first SMRs. The Amentum-led joint venture, known as Litmus Nuclear , will play a pivotal role in the SMR program by delivering independent assurance and expert technical guidance across critical areas, including design, safety, engineering, construction, and commissioning. This support is designed to help GBE-N achieve its goal of securing a final investment decision for the deployment of SMRs at the Wylfa site. "This award recognizes Amentum’s expertise to accelerate the global expansion and revitalization of nuclear energy. It also underscores our central role in advancing the UK’s nuclear ambitions, complementing our ongoing work at Hinkley Point C and Sizewell C,” said Loren Jones, senior vice president and head of Amentum’s Energy & Environment-International business. “Amentum will draw upon our expertise in nuclear science and engineering to provide independent technical and delivery assurance, helping GBE-N advance the SMR program and bolster the UK’s energy security and industrial base.” The joint venture will also ensure the SMR program meets regulatory requirements and is poised to deliver reliable, low-carbon power for decades to come. In November 2025, the UK’s Department for Energy Security and Net Zero announced Wylfa, on the island of Anglesey/Ynys Môn, as the site for the country’s first SMR’s. These 470MWe reactors are smaller and designed to be built more quickly than some traditional nuclear power stations. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. About Amentum in the United Kingdom With more than 6,000 people in the UK, Amentum is the delivery partner for project and construction management services at Hinkley Point C; sole program and project management delivery partner at

HONOLULU--(BUSINESS WIRE)-- Amentum (NYSE: AMTM) announces the relocation of its Hawaii office from Aiea to a new, significantly larger facility at 3375 Koapaka Street in Honolulu. This strategic move quadruples the size of Amentum’s local headquarters and reflects the company’s commitment to bolstering U.S. Indo-Pacific Command (USINDOPACOM) mission delivery in the region. The expansion also includes the establishment of a new Center for Contested Logistics , a cutting-edge hub aimed at addressing one of modern warfare’s most critical challenges. Image credit: Captain Jared McCully, U.S. Army “Our mission is to transform contested logistics from a strategic vulnerability into a decisive advantage,” said Mark Walter, president of Amentum’s Engineering and Technology Group. “By expanding our local headquarters, we are centralizing our regional operational and solutions development teams alongside our Hawaii-based customers and teams to enable greater agility and responsiveness. This investment enhances our ability to scale operations, rapidly develop solutions and adapt to the evolving security dynamics in the Asia-Pacific region.” The Indo-Pacific region has emerged as one of the United States’ highest strategic priorities. Anti-access/area-denial (A2/AD) strategies in the region pose significant risks to communication networks, supply lines, and cyber infrastructure. Maintaining mission readiness in this complex environment requires resilient systems capable of adapting to long-range disruptions while ensuring operational independence. As the U.S. military’s oldest and largest unified command, USINDOPACOM plays a pivotal role in defending U.S. interests, deterring aggression, and promoting regional security and stability. “This move is a clear signal of our long-term commitment to the Indo-Pacific and to the warfighters we sit with and support every day, strengthening our ability to operate, innovate, and prevail in contested environments," said Brian Bethea, vice president of Amentum’s Indo-Pacific Mission Integration Program. Amentum’s contributions to USINDOPACOM’s mission are broad and multifaceted, managing over 1,000 people across the Hawaiian Islands. The company’s key programs in the region include: INDOPACOM Technology, Experimentation, Analysis, and Management Services (ITEAMS): This initiative drives advanced analysis, experimentation, and testing to optimize Department of Defense operations and align with USINDOPACOM’s priorities. Pacific Missile Range Facility (PMRF) Contract: Partnering with a Native Hawaiian-owned firm, Amentum delivers leading-edge technological solutions and sustainment capabilities to support PMRF operations. Comprehensive Support Services: From intelligence analysis and logistics to supply chain management and aircraft maintenance, Amentum provides critical services to ensure operational readiness across the region. With these programs and its newly expanded regional headquarters, Amentum continues

CHANTILLY, Va.--(BUSINESS WIRE)-- A joint venture led by Amentum (NYSE: AMTM) has won a new framework contract as the lead decommissioning and waste management contractor for nuclear research sites in four European countries. Pavol Stuller, Amentum’s European Development Director, and Laurent Jerrige, JRC Director for Nuclear Decommissioning, signing the contract. Under the $112 million (€95.7 million) contract, awarded by the European Commission Joint Research Centre (JRC), the Amentum-led JV will provide decommissioning solutions to accelerate the cleanup efforts of JRC sites in Ispra (Italy), Karlsruhe (Germany), Geel (Belgium) and Petten (The Netherlands). “Amentum’s robust track record of delivering European-funded projects on time and on budget in multiple countries, including prior experience working at JRC Ispra, made us the ideal choice for this contract,” said Loren Jones, senior vice president and head of Amentum’s Energy & Environment-International business. “We will leverage decommissioning and waste management techniques developed at the world’s most complex nuclear sites, integrating innovative solutions to complex technical and project management challenges. Additionally, our strong ties to regulatory authorities across the European Union will serve as a vital asset in ensuring success.” For more than 60 years, the JRC sites have addressed complex challenges in areas such as nuclear decommissioning, innovation, safeguards and non-proliferation by conducting research, providing scientific advice and supporting European Union policy makers. The decommissioning and waste management contract will cover structures such as research reactors, hot cells, accelerators, laboratories and other infrastructure where radioactive substances have been handled. The work will be delivered by an Amentum-led joint venture with WSP Italia, supported by sub-contractors TUV Rheinland and Protection Solution SRL. The JV’s scope of work includes licensing, radioactive waste management, radiation protection, decommissioning and nuclear engineering, worksite management and safety, non-nuclear engineering, facility supervision and quality assurance. The JRC contract has a duration of two years with three potential two-year extensions. About Amentum Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. In Europe, Amentum has more than 6,500 people driving the nuclear resurgence in the UK, France, Poland, Slovakia and the Netherlands. Key nuclear energy programs include Hinkley Point C, Sizewell C and Rolls-Royce SMR in the UK, ITER in France, and advising the Polish and Dutch governments on nuclear new build. To su

State-of-the-art Hub, featuring a Next-Gen Technology Showcase, to Open in 2027 Amentum (NYSE: AMTM), a global leader in advanced engineering and technology solutions, will open a new worldwide headquarters in Reston, Virginia in early 2027. Image courtesy of Comstock The company has signed a 45,000-square-foot lease at 1900 Reston Metro Plaza located in the heart of Reston Station’s Metro Plaza District. The LEED-Gold certified building designed by world-renowned architect Helmut Jahn, is a sixteen-story office tower with immediate access to Metro’s Silver Line with exceptional connectivity across the Washington, D.C. region. "Amentum’s investment in our new Northern Virginia hub at Reston Station reflects the expanding opportunities of our company and where we are headed,” said Amentum’s chief operating officer, Steve Arnette. “This modern headquarters, featuring a next-generation Technology Showcase, will bring our teams together and serve as a destination for customers, employees,

Amentum (NYSE: AMTM) has been selected to provide missile design engineering and program management expertise to advance the UK’s ambition for hypersonic strike capabilities. The Industry Mission Partner (IMP) contract was awarded by Team Hypersonics UK, part of the Ministry of Defence, to accelerate weapon development and sovereign capability while bolstering collaboration with Australia and the United States through the AUKUS agreement. An impression of a hypersonic missile. Image credit: courtesy of the Ministry of Defence. Amentum will set up a Joint Programme Office and System Engineering Delivery Advisory Team to conduct detailed development of engineering design requirements for the MOD’s hypersonic weapon system demonstrator and examine options for flight testing. As part of the IMP contract, Amentum will deliver project lifecycle solutions, including systems engineering, mission planning, sensor platform integration, test design, planning and execution, safety systems, and

Revenues of $3.24 billion Net Income of $44 million; Adjusted EBITDA of $263 million Diluted Earnings Per Share of $0.18; Adjusted Diluted Earnings Per Share of $0.54 Backlog of $47.2 billion; Book-to-Bill of 1.0x, Last Twelve Months 1.1x Moody's Upgraded Credit Rating to Ba3, from Ba1 Amentum Holdings, Inc. (“Amentum” or the “Company”) (NYSE: AMTM), a leading advanced engineering and technology company, today announced results for the first quarter ended January 2, 2026, and reaffirmed its outlook for fiscal year 2026. “Amentum’s first-quarter results reflect solid operational performance and continued progress on our strategic objectives,” said Amentum Chief Executive Officer John Heller. “Robust bookings across our accelerating growth markets reinforce the strength of our strategy that focuses on the high-demand mission areas of global nuclear energy, space systems and technologies, and critical digital infrastructure. As a result, we remain well positioned to deliver on our fiscal