5 U.S.C. § 5521: Definitions

For the purpose of this subchapter—(1) “agency” means—(A) an Executive agency; (B) the judicial branch; (C) the Library of Congress; (D) the Government Publishing Office; and (E) the government of the District of Columbia; (2) “employee” means an individual employed in or under an agency; (3) “head of each agency” means—(A) the Director of the Administrative Office of the United States Courts with respect to the judicial branch; and (B) the Mayor of the District of Columbia with respect to the government of the District of Columbia; and (4) “United States”, when used in a geographical sense, means the several States and the District of Columbia.