Will be closed from March 28th, though sometime in Fall.
https://www.si.edu/newsdesk/releases/smithsonians-national-air-and-space-museum-will-temporarily-close-renovation
"Quasi-Federal" sounds familiar...
Most of it has been closed for renovations for the past year.
I had a friend visiting last October and we were going to do, and only 2 or 3 of the sections were open.
The Udvar-Hazy is open. Some of the aircraft have plastic sheeting over them, as they are doing some work on the roof.