Originally Posted by
be_rettSEA
This is the case at pretty much any airport where TSA is operating.. As long as you have a valid same-day boarding pass, you can enter through any checkpoint to access concessions, lounges, etc. You may get someone at the "pre checkpoint area" letting you know you're not at the right terminal, but other than that, TSA only cares you have a flight leaving from that airport that day.
I feel like JFK is the most strict perhaps due to having totally separate terminal buildings.