Pittsburgh International Airport (PIT)
Tampa International Airport (TPA)
Detroit Metropolitan Wayne County Airport (DTW)
With Detroit Metro Airport as the latest addition, non-ticketed individuals can access gate areas, after security. At DTW, this includes both terminals (North and McNamara).
You can't just walk on in. You still have to go through security like ticketed passengers.
At Detroit, they have implemented a the “DTW Destination Pass”. The intention is to allow non-passengers to access the airport to go to restaurants, view exhibits, plane and/or people watch, walk with a friend or family member to their departure gate, or meet your traveler(s) when at their arrival gate.
According to a spokesperson for DTW, the new regulations allow them to expand the gate pass program that already exists for Westin hotel guests. The DTW Destination Pass is currently in a pilot stage, with a termination date (of pilot) set for Jan. 5, 2020.
Don't forget, you still need to check airport TSA Security Wait Times, even if you are entering these airports without a ticket.
Will other airports follow?