It is documented that the initial requirements for IOC were downgraded.and when you've finished arguing with the USAF you'll have to go argue with the Marines as well, they have 2 operational f35 squadrons (their designation) as well now, transition from AV-8B Harriers is complete for both.
https://news.usni.org/2016/05/13/3r...older-planes-ready-an-operational-perspective
The achievement of IOC for the A and B models was in effect a PR exercise.
