40 U.S.C. § 8144

During April, May, and June of each year, the Administrator of General Services may deliver to all branches of the Federal Government and the government of the District of Columbia as much fuel for their use during the following fiscal year as may be practicable to store at the points of consumption. The branches of the Federal Government and the government of the District of Columbia shall pay for the fuel from their applicable appropriations for that fiscal year.