The United States Air Force operates the world’s largest fleet of Lockheed Martin F-35 stealth fighters, but the exact number isn’t always obvious at first glance. The program is constantly in motion: new aircraft roll off the production line, squadrons are activated or reshuffled, and older jets rotate through training units or scheduled maintenance. With the F-35 gradually becoming the centerpiece of the Air Force’s future fighter inventory, having a clear sense of how many are actually in service, and how rapidly that number is growing has become increasingly important for anyone following US military aviation.
In this article, we will take a closer look at the size of the USAF’s F-35A fleet today and explain what counts toward that total. We will also explore the main forces shaping the fleet’s growth, how the Air Force thinks about its long-term needs, and how this compares to what other countries are buying. Experts expect the F-35 to remain the backbone of American airpower for decades, so understanding where things stand now is a good window into where the service is headed.
Counting The USAF’s F-35 Fleet: How Many Are In Service?
In mid-2025, the US Air Force took delivery of its 500th F-35, making it, no doubt, the largest operator of the aircraft. That count includes combat aircraft, training jets, and airframes dedicated to test work. That milestone was marked by the Florida Air National Guard’s 125th Fighter Wing, highlighting both how the F-35 is expanding within Guard units and how delivery has progressed despite technical setbacks.
The number continues to rise steadily as Lockheed Martin completes new deliveries and the Air Force brings fresh aircraft into operational service. It’s a pace that’s been consistent for several years, even as upgrades and new software blocks continue to be introduced.
These aircraft are spread across a widening group of bases, including major hubs such as Luke AFB for training, Hill AFB for early operational units, and Nellis AFB for tactics and evaluation missions. Several Air National Guard bases have also joined the F-35 community, reflecting how widely the aircraft is being adopted across the service.
As additional squadrons begin flying the F-35, the Air Force is steadily phasing out many of its older fighters, most notably the long-serving F-16s. Some of those jets are retired outright, while others are shifted into secondary roles, such as training or support assignments. Each step in this process opens up personnel capacity, maintenance space, and budget room, all of which make it easier for the F-35 program to grow at a measured, predictable pace.
One important detail is that the number of aircraft physically delivered and the number “ready to fly” aren’t always the same. Some jets spend extended time going through upgrades, software improvements, or scheduled heavy maintenance. Others remain tied to pilot training or test work and are not part of the deployable force. Even so, the total fleet figure of 500 remains the clearest representation of how large the USAF’s investment has become.
What Determines The Jets’ Airworthiness?
Various forces shape the size and the usage of the F-35 fleet, and most of them come down to long-term planning rather than day-to-day decisions. The F-35 is replacing multiple older aircraft types, which means its growth is tied to how quickly those aging fleets are phased out, how much funding Congress approves for new fighters each year, and how smoothly the production and modernization pipeline runs. Because the aircraft is continually updated with new software and hardware, each year brings a mix of new deliveries and older jets temporarily going out of service for scheduled upgrades.
A major influence is the retirement schedule for the legacy fleet. Every time the Air Force intervenes on the divestment of older fighter jets, that affects how many F-35s are needed to fill the gap. Another important factor is the series of updates known as Technology Refresh packages and Block upgrades. These changes help the aircraft remain competitive but sometimes require extra testing or integration time, which can temporarily slow deliveries or even pause them for a few months.
Global events can also influence the size of the “ready” fleet at any given time. When deployments surge, or tensions rise, the Air Force tends to keep more aircraft available for operations, which can delay planned upgrade work. This flexibility helps the service adapt to changing circumstances, but it also leads to variation in the number of jets that are fully mission-capable at any moment.
What US Air Force Bases Have F-35s?
Ten air force bases are listed as bases for the USAF F-35A, although they can operate from many more bases.
Voices From The Top: What Air Force Leaders Say
Air Force leadership has been quite clear: the F-35 is a foundational aircraft for its future. Gen. Charles Q. Brown Jr., Chief of Staff of the US Air Force, during a 2021 press conference, called it
“the cornerstone of our fighter fleet … for the foreseeable future”
It confirmed how the F-35 remains central to the Air Force’s long-term plans.
Other senior officials back him up. Air Force Secretary Frank Kendall has stated that the F-35 isn’t going anywhere, calling it “a state-of-the-art system that’s continuously being upgraded” and arguing that there’s simply no near-term alternative to its capabilities.
Analysts tracking the program closely also note real, practical bottlenecks. They point out that growth can slow when training facilities, depot maintenance capacity, or software certification processes lag behind aircraft deliveries. Perhaps most telling, however, is the long-term vision: planning documents still call for 1,763 F-35s, a figure that has persisted through multiple leadership changes. Gen. Brown himself has reaffirmed this target, which underscores just how central the F-35 remains to the Air Force’s future.
A Global Comparison: How The USAF Stacks Up
Around the world, a growing number of nations operate the F-35, but none come close to the scale of the United States Air Force. Other countries generally field between a few dozen and just over one hundred aircraft, and most expect their fleets to grow gradually. The US Navy and Marine Corps also operate their own versions of the fighter, which pushes the overall US total far beyond what any other country plans to maintain.
Even the largest foreign fleets, like those of Japan, South Korea, and Italy, remain well below the USAF’s totals. This gap is understandable given the size of the US Air Force and the range of global missions it supports. The American fleet has to fulfill roles that, in other countries, are often divided among several different aircraft types.
|
Operator |
Approx. Delivered / In‑Service |
Planned / Program of Record |
Variants |
|---|---|---|---|
|
USAF |
~500 F‑35As (as of mid‑2025) |
1,763 |
F‑35A |
|
USMC |
~120 F‑35Bs |
245 |
F‑35B |
|
US Navy |
~100 F‑35Cs |
351 |
F‑35C |
|
Japan |
~75 F‑35As |
147 |
F‑35A/B |
|
Italy |
~90 F‑35A/B |
115 |
F‑35A/B |
This comparison underscores how influential the Air Force’s decisions are. When the USAF shifts its procurement tempo or introduces a new upgrade, those changes often echo across the international F-35 community.
The 14 US Allies Participating In The F-35 Lightning II Program
Fourteen allied nations unite with the US with one purpose – the F-35 program, forging a renewed partnership.
Challenges And Bottlenecks: Why The Numbers Aren’t Always Straightforward
Even though the USAF operates the largest F-35 fleet in the world, several challenges can affect how many aircraft are available for daily missions. One persistent issue is software development and integration. Each new Block or Technology Refresh update can briefly slow deliveries and reduce the number of aircraft fully ready for operations while engineers and maintainers update flight systems.
Supply chain constraints have also occasionally affected F-35 operations. Specialized components, from landing gear assemblies to avionics parts, can experience temporary shortages, delaying maintenance or slowing the introduction of newly delivered jets into active service. These delays are often magnified by the program’s global scale, with parts flowing to multiple nations simultaneously.
Because of the aircraft’s complexity, its maintenance and upgrade cycle also plays a role. A certain portion of the fleet will always be in depots receiving heavy work, and training squadrons require numerous aircraft that do not deploy. These factors mean that the number of jets “on hand” is always higher than the number “ready to go,” which is normal for modern fighters. Air Force officials say they expect overall availability to improve as more maintainers gain experience and as the newest block configurations mature. Over time, those improvements should help stabilize the number of aircraft that are mission-ready.
Looking Ahead: Why The F-35A Will Remain At The Center Of Air Force Operations
As of mid-2025, the US Air Force has about 500 F-35A fighters in its inventory, making it the largest F-35 fleet in the world. That number includes jets across active-duty wings, Air National Guard units, training squadrons, and test assignments. Not every plane is always ready to deploy: some are in maintenance, undergoing upgrades, and others are being used for training. The overall trend is clear: the F-35A is quickly becoming the heart of the Air Force’s fighter fleet. Even with occasional pauses for software updates or new hardware integration, the fleet keeps growing steadily.
The F-35A is becoming the main aircraft of the Air Force’s operations, thanks to its flexibility. Bases across the US and in the NATO countries are standing up new squadrons, and Air National Guard units are increasingly flying the jet, too. Meanwhile, older aircraft like F-16s are being retired or reassigned, freeing up personnel, maintenance capacity, and funding to support the F-35’s expansion. This careful balancing act and standardization ensure the Air Force can grow its fleet efficiently without overextending resources.
Looking to the future, the Air Force plans to acquire up to 1,763 F-35As. That means the 500 jets in service today are just the beginning. As more aircraft arrive and modernization programs like Block 4 roll out, the number of combat-ready jets will rise, giving the Air Force more flexibility and readiness. With this growth, the USAF will continue to dominate globally when it comes to F-35 operations, shaping not just its own capabilities but also influencing how allied nations use and upgrade their fleets.
