5 C.F.R. § 9701.202 – Coverage.

(a) This subpart applies to eligible DHS employees and positions listed in paragraph (b) of this section, subject to a determination by the Secretary or designee under § 9701.102(b).
(b) The following employees and positions are eligible for coverage under this subpart:
1. (1) Employees and positions that would otherwise be covered by the General Schedule classification system established under 5 U.S.C. chapter 51;
2. (2) Employees and positions that would otherwise be covered by a prevailing rate system established under 5 U.S.C. chapter 53, subchapter IV;
3. (3) Employees in senior-level (SL) and scientific or professional (ST) positions who would otherwise be covered by 5 U.S.C. 5376; and
4. (4) Members of the Senior Executive Service (SES) who would otherwise be covered by 5 U.S.C. chapter 53, subchapter VIII, subject to § 9701.102(d).