Another box ticked.
From Flight Global:-
The US Navy declared the Lockheed Martin F-35C Lightning II, the aircraft carrier-capable variant of the stealth fighter, to have achieved Initial Operational Capability (IOC) on 28 February.
The declaration comes shortly after the USN’s first F-35C squadron, Strike Fighter Squadron 147, completed aircraft carrier qualifications aboard USS Carl Vinson and received a Safe-For-Flight Operations Certification, the service said. The US Air Force declared IOC for its conventional-takeoff and landing F-35A in 2016 and the US Marine Corps’ short-takeoff-and-vertical-landing F-35B was declared IOC in 2015 – meaning all US variants are now operational.