Sleeping overnight at Reagan National (DCA) airport

Question

I am trying to book a domestic flight to Ronald Reagan Washington National Airport (DCA) at the end of this month. The itinerary I am looking is such that the flight will land at DCA at around 11:00 P.M, which I am assuming will be the last flight of the day. I'm moving into my new apartment the very next day, but I won't most likely have a place to stay overnight, so I am thinking of crashing at the airport in the lounge where the plane lands, and then waking up in the morning and catching a ride to my new place.

Is this allowed etc., especially at large airports located in large urban centers?

Answer 1

tl;dr It should be fine, if not necessarily comfortable. Depending on your budget and interest in roughing it, an airport hotel room would be a reasonable alternative.

From Sleeping in Airports and specifically from their Washingon Reagan Airport sleep guide:

While Washington Dulles [sic] Airport is technically open 24-hours, the Security checkpoints and Secure areas do close for the evening, likely by 11:00 PM. Even if you’re already inside Security, you may have to relocate to the pre-Secure area.

Since you asked in comments, that basically means you'll have to go out through the security checkpoints: you won't be able to stay "in the lounge where the plane lands".

Most seating here is equipped with armrests, so don’t expect too much comfort. Maybe travellers report sleeping on the floor, particularly near the heat vents next to the windows. A sleep mat or sleeping bag will provide some much-needed cushion.

Airport security don’t seem to mind overnight campers, as long as you stick to the pre-Security areas at night.

The site has more details about temperature (generally cold), brightness (generally bright), and other tips.