5 USC 5332 - The General Schedule
(a)
(1) The General Schedule, the symbol for which is GS, is the basic pay schedule for positions to which this subchapter applies. Each employee to whom this subchapter applies is entitled to basic pay in accordance with the General Schedule.
(2) The General Schedule is a schedule of annual rates of basic pay, consisting of 15 grades, designated GS1 through GS15, consecutively, with 10 rates of pay for each such grade. The rates of pay of the General Schedule are adjusted in accordance with section 5303.