5 USC 8114 – Computation of pay
(a) For the purpose of this section—
(1) “overtime pay” means pay for hours of service in excess of a statutory or other basic workweek or other basic unit of worktime, as observed by the employing establishment; and
(2) “year” means a period of 12 calendar months, or the equivalent thereof as specified by regulations prescribed by the Secretary of Labor.
(b) In computing monetary compensation for disability or death on the basis of monthly pay, that pay is determined under this section.
(c) The monthly pay at the time of injury is deemed one-twelfth of the average annual earnings of the employee at that time. When compensation is paid on a weekly basis, the weekly equivalent of the monthly pay is deemed one-fifty-second of the average annual earnings. However, for so much of a period of total disability as does not exceed 90 calendar days from the date of the beginning of compensable disability, the compensation, in the discretion of the Secretary of Labor, may be computed on the basis of the actual daily wage of the employee at the time of injury in which event he may be paid compensation for the days he would have worked but for the injury.
(d) Average annual earnings are determined as follows:
(1) If the employee worked in the employment in which he was employed at the time of his injury during substantially the whole year immediately preceding the injury and the employment was in a position for which an annual rate of pay—
(A) was fixed, the average annual earnings are the annual rate of pay; or
(B) was not fixed, the average annual earnings are the product obtained by multiplying his daily wage for the particular employment, or the average thereof if the daily wage has fluctuated, by 300 if he was employed on the basis of a 6-day workweek, 280 if employed on the basis of a 5½-day week, and 260 if employed on the basis of a 5-day week.
(2) If the employee did not work in employment in which he was employed at the time of his injury during substantially the whole year immediately preceding the injury, but the position was one which would have afforded employment for substantially a whole year, the average annual earnings are a sum equal to the average annual earnings of an employee of the same class working substantially the whole immediately preceding year in the same or similar employment by the United States in the same or neighboring place, as determined under paragraph (1) of this subsection.
(3) If either of the foregoing methods of determining the average annual earnings cannot be applied reasonably and fairly, the average annual earnings are a sum that reasonably represents the annual earning capacity of the injured employee in the employment in which he was working at the time of the injury having regard to the previous earnings of the employee in Federal employment, and of other employees of the United States in the same or most similar class working in the same or most similar employment in the same or neighboring location, other previous employment of the employee, or other relevant factors. However, the average annual earnings may not be less than 150 times the average daily wage the employee earned in the employment during the days employed within 1 year immediately preceding his injury.
(4) If the employee served without pay or at nominal pay, paragraphs (1), (2), and (3) of this subsection apply as far as practicable, but the average annual earnings of the employee may not exceed the minimum rate of basic pay for GS-15. If the average annual earnings cannot be determined reasonably and fairly in the manner otherwise provided by this section, the average annual earnings shall be determined at the reasonable value of the service performed but not in excess of $3,600 a year.
(e) The value of subsistence and quarters, and of any other form of remuneration in kind for services if its value can be estimated in money, and premium pay under section 5545(c)(1) of this title are included as part of the pay, but account is not taken of—
(1) overtime pay;
(2) additional pay or allowance authorized outside the United States because of differential in cost of living or other special circumstances; or
(3) bonus or premium pay for extraordinary service including bonus or pay for particularly hazardous service in time of war.