Some properties have one specific federal gov't rate and one for state gov't; sometime higher, sometimes lower, depending on the federal and state per diems in the locale. At one time you could count on any available government rate at any Marriott to be no higher than the federal per diem in the particular locale. This is, unfortunately, no longer true. Instead, at some properties the government rate has become just another discount, not pegged to the local per diem. If the goverment traveler books this rate, without double-checking the local per diem, he/she could end up shelling out for government business travel out of his/her own pocket. Even worse, few federal government travelers will book at this over per-diem government rate, leaving the rate to be used by folks seeking discounts who don't mind impersonating government employees at checkin.
There is a contracted government rate available at many properties called the "Fedrooms" rate. By contract, this rate must be no higher than local per diem, and must have same day cancellation no earlier than 4 p.m. While I've seen this rate available at Hiltons, I've yet to see a Marriott family property offer this rate.
www.fedrooms.com