StacksVerified U.S. regulatory reference

5 CFR §839.401

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
If you were placed in CSRS or CSRS Offset due to a qualifying retirement coverage error and you should have been in FERS, you may elect CSRS Offset or FERS. If you were placed in CSRS or CSRS Offset due to a qualifying retirement coverage error and you should have been in Social Security-Only, you may elect CSRS Offset or Social Security-Only. This is summarized in the following chart: