5 CFR § 839.1101
How are my retirement benefits computed if I elect CSRS or CSRS Offset under this part?
November 4, 2020
Unless otherwise stated in this part, your retirement benefit is computed as if you were properly put in CSRS or CSRS Offset on the effective date of the error. All the eligibility and benefit computation rules for CSRS or CSRS Offset apply to your retirement benefit.