Government Pay Schedule (GS). The General Schedule (GS) is the Federal government's main pay system and is composed of 15 grades (GS1 to GS15), or salary levels. Each grade includes ten steps through which employees advance based on satisfactory job performance and length of service. Locality pay is based on surveys done by the Bureau of Labor Statistics. Locality pay is designed to make up the pay gaps between Federal and non-Federal salaries in local areas.