Practically any employment with the federal government or the District of Columbia (if first employed by the D.C. government before October 1, 1987), that was not covered under CSRS, including employment covered by Social Security withholdings, is creditable for retirement purposes, so long as the employee is covered by CSRS/CSRS-Offset at some later date.
The employee is allowed to pay a monetary deposit for it, either to avoid a reduction in the amount of annuity or, in some cases, to receive credit for the service at all. Even employment covered by another federal retirement system (such as TVA, foreign service, etc.) is creditable provided the employee is not receiving any benefits for that time under the other system. Generally an individual obtains a refund of contributions under the other system and deposit the refund, with interest, in the Civil Service Retirement and Disability Fund to receive any credit for that period of time.
Anyone working for the federal government or the District of Columbia prior to October 1, 1982, in positions for which deductions for CSRS were not made will receive limited credit for this service in the computation of a CSRS/CSRS-Offset annuity. Specifically, the period will count when computing length of service. However, the annuity will be reduced by one-tenth of the amount that the employee would have paid into CSRS plus interest had the service been covered by CSRS.
Anyone working for the federal government or the District of Columbia after October 1, 1982, in positions for which CSRS deductions were not made will have to make the required deposit before that service can be used in any annuity computation. If the deposit is not made, the time involved can still be counted for meeting the minimum length of service for an immediate annuity, and for determining high-3 average salary. However, no credit will be allowed in the computation of the annuity — that is, the time will not be multiplied by a percentage of the high-3 average salary.