F-35 variants share 20% common parts, with the F-35C having 40% unique components

The F-35A is slated to replace the Air Force's F-16 and A-10, the F-35B will replace the Marine Corps' AV-8B Harrier, and the F-35C is set to replace the Navy's F/A-18 Hornet, with Lockheed Martin using a cousin component approach that keeps about 20% of parts common across all three variants while the F-35C contains about 40% entirely unique parts.

All versions share the Pratt & Whitney F135 engine, internal cockpit layout, radar system, weapons suite, and baseline weapon compatibility; the F-35B employs a shaft‑driven LiftFan that reduces fuel tank space, and the F-35A is the only model equipped with an integrated internal cannon mounted inside the fuselage.