5 CFR 839.1003 - How will OPM compute the amount of lost earnings?
(a) Lost earnings will generally be computed in accordance with the Board's lost earnings regulations (5 CFR 1606 of chapter VI). However, the FERCCA states that OPM may compute the lost earnings in an alternative manner if such a computation is not administratively feasible. The alternative manner will yield an amount that is as close as practicable to the amount computed under 5 CFR 1606 of chapter VI.
(b) Your employer is required to submit to OPM all information required to compute the amount of lost earnings.