Check the www.gsa.gov site under Travel on Government Business, then Lodging. Some chains will give you the last room available at a gov't rate, while others only offer it only until the hotel reaches a certain occupancy factor. If your an elite level and can't get a web reservation at a gov't rate, then use the 800 number and have them call the hotel directly on your behalf; they don't really want to walk a high tier customer. Good luck.