5 C.F.R. § 2635.804
This section implements the outside earned income limitations applicable to certain Presidential appointees. The outside earned income limitations applicable to covered noncareer employees, as defined in § 2636.303(a) of this chapter, are implemented in §§ 2636.301 through 2636.304 of this chapter.
(b) Definitions. For purposes of this section:
(2) Presidential appointee to a full-time noncareer position means any employee who is appointed by the President to a full-time position described in 5 U.S.C. 5312 through 5317 or to a position that, by statute or as a matter of practice, is filled by Presidential appointment, other than:
(iv) A position in which a member of the Foreign Service is serving that does not require advice and consent of the Senate.
Example 1 to paragraph (b)(2): A career Department of Justice employee who is detailed to a policy-making position in the White House Office that is ordinarily filled by a noncareer employee is not a Presidential appointee to a full-time noncareer position.
Example 2 to paragraph (b)(2): A Department of Energy employee appointed under § 213.3301 of this title to a Schedule C position is appointed by the agency and, thus, is not a Presidential appointee to a full-time noncareer position.