5 C.F.R. § 831.2103
Employee shall have the same meaning as in 5 U.S.C. 8331(1) .
Estimated earnings is an estimate of basic pay for a period of military service, as determined by an authorized official of the Department of Defense the Department of Transportation, the Department of Commerce, or the Department of Health and Human Services.
Fund is the Civil Service Retirement and Disability Fund.
Member shall have the same meaning as in 5 U.S.C. 8331(2) .
OPM is the Office of Personnel Management.
Period of service is the total years, months, and days from date of initial entry on active duty (or January 1, 1957, if that is later) to date of final discharge for enlisted military personnel, and to date of final release from active duty for officers and reservists. "Period of service" includes consecutive periods of service where there is no break in service, but does not include any lost time.
Service is active honorable military service performed after December 31, 1956.
Sufficient evidence of basic pay for service exists when the employee, Member, or survivor eligible to make a deposit for service provides copies of all official military pay documents, as identified in instructions published by OPM, which show the exact basic pay he or she received for a full period of service. If an employee, Member, or survivor does not have sufficient evidence of basic pay, he or she shall obtain a statement of estimated earnings from the appropriate branch of the military service.
Survivor shall have the same meaning as in 5 U.S.C. 8331(10) .
5 C.F.R. §831.2103