This subpart applies to an employee as defined in 5 U.S.C. 5541(2) who is employed by an agency. In accordance with section 1111 of Public Law 110-181, an employee whose pay is fixed and adjusted from time to time in accordance with prevailing rates under subchapter IV of chapter 53 of title 5, United States Code, or by a wage board or similar administrative authority serving the same purpose, is covered by this subpart effective April 27, 2008.