5 C.F.R. § 550.162 : Administrative Personnel — OFFICE OF PERSONNEL MANAGEMENT — CIVIL SERVICE REGULATIONS — PAY ADMINISTRATION (GENERAL) — PREMIUM PAY —GENERAL RULES GOVERNING PAYMENTS OF PREMIUM PAY ON AN ANNUAL BASIS — Payment provisions

(a) Except as otherwise provided in this section, an employee's premium pay on an annual basis under § 550.141 or § 550.151 begins on the date that he enters on duty in the position concerned for purposes of basic pay, and ceases on the date that he ceases to be paid basic pay in the position.
(b) When an employee is in a position in which conditions warranting premium pay on an annual basis under § 550.141 or § 550.151 exist only during a certain period of the year, such as during a given season, an agency may pay the employee premium pay on an annual basis only during the period he is subject to these conditions.
(c) An agency may continue to pay an employee premium pay on an annual basis under § 550.141 or § 550.151:
(1) For a period of not more than 10 consecutive prescribed workdays on temporary assignment to other duties in which conditions do not warrant payment of premium pay on an annual basis, and for a total of not more than 30 workdays in a calendar year while on such a temporary assignment.
(2) For an aggregate period of not more than 60 prescribed workdays on temporary assignment to a formally approved program for advanced training duty directly related to duties for which premium pay on an annual basis is payable.

An agency may not continue to pay an employee premium pay on an annual basis under this paragraph for more than 60 workdays in a calendar year.

(d) When an employee is not entitled to premium pay on an annual basis under § 550.141, he is entitled to be paid for overtime, night, holiday, and Sunday work in accordance with other sections of this subpart.
(e) An agency shall continue to pay an employee premium pay on an annual basis under § 550.141 or § 550.151 while he is on leave with pay during a period in which premium pay on an annual basis is payable under paragraphs (a), (b), and (c) of this section.
(f) Unless an agency discontinues authorization of premium pay under § 550.141 or § 550.151 for all similar positions, it may not discontinue authorization of such premium pay for an individual employee's position-
(1) During a period of paid leave elected by the employee and approved by the agency in lieu of benefits under the Federal Employees' Compensation Act, as amended ( 5 U.S.C. 8101 et seq. ), following a job-related injury;
(2) During a period of continuation of pay under the Federal Employees' Compensation Act, as amended ( 5 U.S.C. 8101 et seq. );
(3) During a period of leave without pay, if the employee is in receipt of benefits under the Federal Employees' Compensation Act, as amended ( 5 U.S.C. 8101 et seq. ). (Note: No premium pay is payable during leave without pay; however, the continued authorization may prevent a reduction in an employee's retirement benefits if the leave without pay period occurs during the employee's high-3 average salary period.)
(g) Notwithstanding paragraph (c)(1) of this section, an agency may continue to pay premium pay under § 550.151 to an employee during a temporary assignment that would not otherwise warrant the payment of AUO pay, if the temporary assignment is directly related to a national emergency declared by the President. An agency may continue to pay premium pay under § 550.151 for not more than 30 consecutive workdays for such a temporary assignment and for a total of not more than 90 workdays in a calendar year while on such a temporary assignment.

5 C.F.R. §550.162

33 FR 12458, 9/4/1968, as amended at 35 FR 6312, 4/18/1970; 64 FR 69175, 12/10/1999; 67 FR 6641, 2/13/2002; 68 FR 4681, 1/30/2003