5 U.S. Code § 3103
5 U.S. Code § 3103 is about Employment at seat of Government only for services rendered. It is under Part 3 (Employees) Subpart B (Employment and Retention) Subchapter 1 (Employment Authorities) Chapter 31 (Authority For Employment) of Title 5 (Government Organizations and Employees) of the Code.
An individual may be employed in the civil service in an Executive department at the seat of Government only for services actually rendered in connection with and for the purposes of the appropriation from which he is paid. An individual who violates this section shall be removed from the service.