Does anyone know if it is possible to get into T4 (past security) to access a lounge if you fly in and out of T5?
Thanks

Google found this ".... None of the terminals [at JFK] interconnect with airside walkways, so you do need to go through security again for a flight connection, apart from Terminals 2 and 4 where there is an airside bus. …" which I think answers your question.

Thanks Pulaski. So i can go through security at T4 even if i don't have a flight from that terminal?

No idea, but I doubt it, as you need to show a valid ticket for a flight, and I am sceptical that you would be allowed through security without a ticket valid for a flight from the terminal that you are seeking access to.

I'm not so sure, I don't know 100% but I've flown through airports and 1 of myself or my wife have used security in a different terminal so we can have dinner together before getting on different flights. I also used T2 security in SFO by mistake once when my flight was from the International terminal which you can't get to airside from T2.

Thanks all. I was enquiring on behalf of daughter #1 making her first solo crossing of the atlantic. She had to check in (again) at JFK and was told she could not enter terminals that she wasn't departing from so she didn't even try. Landed safely at DUB a few hours later and is now staying with an aunt at the start of her 5 week pre-college visit to UK