If you were placed in FERS due to a qualifying retirement coverage error and you should have been in CSRS, you may elect FERS or CSRS. If you were placed in FERS due to a qualifying retirement coverage error and you should have been in CSRS Offset, you may elect FERS or CSRS Offset. If you were placed in FERS due to a qualifying retirement coverage error and you should have been in Social Security-Only, you may elect FERS or Social Security-Only. This is summarized in the following chart: