The US Air Force plans to more than double its planned F-15EX Eagle II fleet, giving Boeing’s upgraded fourth-generation fighter a larger role in the service’s future plans as defense spending rises.
The service now plans to buy 267 F-15EX fighters, up from a previous plan for 129 aircraft. The increase would add 138 aircraft to the planned fleet and mark a shift for a program that has evolved numerous times since the Air Force first selected the type.
The F-15EX fleet expansion is part of the Pentagon’s fiscal 2027 budget request, which seeks $1.5 trillion in total defense resources. The White House said the proposal would increase defense funding by $441 billion, or 44%, compared with 2026.
The Air Force’s 2027 budget request includes $3 billion for 24 F-15EX fighters. The same request includes $7.4 billion for 38 F-35 fighters, $1.1 billion for Collaborative Combat Aircraft, $3.9 billion for 15 KC-46A tankers and $3.2 billion for the B-21 bomber.
The F-15EX is the newest version of the F-15, a fighter family that first entered US Air Force service in the 1970s. Boeing builds the aircraft in St. Louis, Missouri.
The Eagle II adds modern avionics, fly-by-wire flight controls, new mission systems and updated electronic warfare capabilities to a non-stealth fighter designed to carry large weapons loads and operate alongside newer aircraft.
The Air Force has used the F-15EX primarily to replace older F-15C and F-15D fighters, many of which date to the 1980s. The larger fleet plan could also allow the service to begin replacing part of its F-15E Strike Eagle inventory, according to multiple reports.
The planned expansion comes as the Air Force adds fifth-generation F-35As and prepares for a future mix that includes crewed fighters and unmanned Collaborative Combat Aircraft.
Air Force officials said during an April 21, 2026, budget briefing that the service needs both the F-35A and F-15EX because the aircraft offer different capabilities.
The F-15EX does not provide the stealth characteristics of the F-35A, but it can carry more weapons and may be useful for homeland defense, air defense and Indo-Pacific missions where payload and range are important.
The Air Force initially discussed buying as many as 144 aircraft, later reduced the expected fleet to 80, then raised it to 104 and 129 before the latest plan calling for 267 fighters.
Congress must still approve the fiscal 2027 budget, and future aircraft buys would depend on the appropriations to go with them.
