[jim macomber]

I don’t know the answer to this but I wonder if Senators - who have residences in Washington as well as their home states - get per diems at one or the other. Or both. Just wondering.

[muawiyah]

Federal per diem rules require you to establish a primary domicile ~ this concept appears under different names in different portions of the travel manual, but the idea is you must decide where you work. I always used Washington DC. Presumably members of Congress do the same.

Travel for the purpose of commuting to work is not reimbursible. I'd guess Joe Biden does not get reimbursed ~ or maybe he does. Someone should find out.

BTW, Congress has its own rules ~ it's a separate branch of government and no one there needs to follow the Executive Branch travel rules ~ although, in general, whatever Congress does in this regard will look pretty much like what everybody else does.