5 CFR 846.102 - Definitions.
In this part -
CSRS means subchapter III of chapter 83 of title 5, United States Code.
CSRS/SS service means service subject to both CSRS deductions (or deductions under another retirement system for Federal employees if such service is creditable under CSRS) and social security deductions as a result of the Social Security Amendments of 1983. For this purpose, the service of an individual is considered CSRS/SS service if the service would have been covered under CSRS except for an election under section 208(a)(1)(A) of the Federal Employees Retirement Contribution Temporary Adjustment Act of 1983 to have no CSRS coverage.
OPM means the Office of Personnel Management.
Social security means coverage under the Old Age, Survivors, and Disability Insurance programs of the Social Security Act.