5 U.S.C. § 5374
Miscellaneous positions in the executive branch
The head of the agency concerned shall fix the annual rate of basic pay for each position in the executive branch specifically referred to in, or covered by, a conforming change in statute made by section 305 of the Government Employees Salary Reform Act of 1964 (78 Stat. 422), or other position in the executive branch for which the annual pay is fixed at a rate of $18,500 or more under special provision of statute enacted before