AECOM

AECOM is one of the largest engineering and construction firms working for the U.S. government, and its government arm sits inside a company whose day job is civil infrastructure everywhere else. The firm traces back to a 1990 management buyout that combined several engineering and construction predecessors, and it now runs its business through Americas and International segments that both carry a government line alongside transportation, water, environment, and facilities work. For the Pentagon, that government line means real weight. AECOM has supported Air Force missions since 1956, Army missions since 1916, and Navy missions since 1927, spanning military construction, environmental remediation, and program management on bases across the country and overseas. The bulk of its defense work is facilities and infrastructure, not hardware. AECOM designs and builds aircraft maintenance hangars, vehicle maintenance shops, training centers, secure office buildings, and troop housing under military construction programs, and it does the same abroad under Foreign Military Sales funding, effectively building out allied bases to U.S. specifications.

A recent Air Force infrastructure and facilities award worth close to two billion dollars runs through this line, alongside a nationwide Department of Homeland Security contract to modernize critical infrastructure. Environmental work is its own substantial piece. AECOM cleans up contamination at current and former defense sites, handles remediation tied to Department of Energy work, and has run environmental programs for the Air Force and at Vandenberg Space Force Base. That overlaps with its civil works and disaster resilience practice, which plans and rebuilds infrastructure after storms, floods, and other disasters, work that increasingly extends into resilience planning for military installations exposed to climate risk. The firm also does program and construction management at scale, the discipline of running a portfolio of federal construction projects on budget and schedule rather than building a single project alone, and it layers advisory and planning services on top for agencies figuring out how to modernize aging infrastructure. Its Army Corps of Engineers relationship runs through decades of civil works and disaster response.

Internationally, AECOM's government reach extends to reconstruction work tied to allied defense ministries and development agencies, plus a strong position on Canada's defense infrastructure source list. AECOM is publicly traded on the New York Stock Exchange under ACM, headquartered in Dallas after relocating from Los Angeles in 2021, and employs roughly 51,000 people worldwide. It is not a hardware manufacturer and does not build weapons or vehicles. What it sells to the defense and intelligence community is the built environment those systems operate from, plus the engineering judgment and program discipline to deliver it on tight federal timelines.