Could be a state law requiring the cashing of such or similar checks… don’t know of a federal law.
U.S. Treasury check deposited in an account of the payee is to be made available the next day. You can place a large deposit exception… $5000 is to be made available according to the bank’s availability schedule for any other deposit (generally next day), then hold the rest of the $$ up to 7 days (U.S. Treasury checks are considered as “local” checks).
Even if you place a hold, for these types of checks, little-to-no protection is given to the bank.
Go here and happy reading! http://www.bankersonline.com/regs/229/229.html