This was a response I received back in 2018, which was right after the last time I tried going to the AC at JFK and was denied to enter the terminal by the American Airlines security checkpoint. I spoke to a friend in Anchorage who is a TSA supervisor prior to entering this time to make sure that this was still the policy. He said as far as he’s aware, as long as you have a valid pass within 24 hours of departure/arrival, you can enter any terminal at that airport. I asked him if he could find the actual written policy, but he has not gotten back to me with it yet.

There was another follow-up email in 2018 where I asked if the contracted employees have the authority to prevent me from entering the TSA Checkpoint Line. His response was:

“The contracted employees do not have the authority to prevent you from entering the TSA checkpoint with a boarding pass. I do not want to speak for American airlines as these contractors follow rules given to them by the airlines. In this instance they were wrong for denying your entry into the security checkpoint.”