CSRS Offset Explained: How It Differs From CSRS and FERS
CSRS Offset is a hybrid that confuses many federal employees. You are covered by CSRS, but you also pay into Social Security — and at age 62 your CSRS pension is "offset" by the Social Security you earned. The good news: your total income usually stays about the same.
- CSRS Offset employees are covered by both CSRS and Social Security.
- At 62, the CSRS annuity is reduced by the Social Security earned during offset service.
- Total income generally stays similar — you are not losing money, just shifting the source.
- It typically applies to employees with a break in service who returned after 1983.
How someone ends up in CSRS Offset
CSRS Offset generally applies to employees who had earlier CSRS-covered service, left federal employment, and then returned after 1983 with at least five years of prior CSRS coverage. Rather than placing them fully into FERS, the rules kept them under CSRS but also enrolled them in Social Security — hence "offset."
How the offset works at 62
While working, a CSRS Offset employee pays reduced CSRS contributions plus Social Security taxes. The CSRS pension is calculated using the normal CSRS formula. Then, at age 62 (or at retirement if later), the CSRS annuity is reduced — "offset" — by the amount of Social Security benefit attributable to the offset service.
A simplified illustration
| Source | Before 62 | After 62 (offset) |
|---|---|---|
| CSRS annuity | $40,000 | $31,000 |
| Social Security | $0 | $9,000 |
| Total | $40,000 | $40,000 |
The figures above are illustrative only. The actual offset equals the lesser of (a) the Social Security benefit attributable to your offset service, or (b) a proportional share based on your years of offset service divided by 40.
A note on WEP and GPO
CSRS Offset employees were historically concerned about the Windfall Elimination Provision and Government Pension Offset. As covered in our WEP/GPO guide, those provisions were eliminated by the Social Security Fairness Act, simplifying the picture for many public retirees.
Estimate your CSRS pension with the CSRS calculator and your Social Security with the Social Security estimator.
Is CSRS Offset worse than regular CSRS?
Generally no. Your total income from the offset CSRS annuity plus Social Security is designed to approximate what a full CSRS pension would have paid.
Does the offset happen if I never claim Social Security?
The CSRS offset is applied at age 62 based on the Social Security you are entitled to from offset service, whether or not you actually file. Coordinate your claiming strategy carefully.
How do I know if I am CSRS Offset?
Check the retirement plan code on your SF-50 and Leave and Earnings Statement, or ask your HR/benefits office for an official determination.
Authoritative references: OPM CSRS and SSA.gov. This site is not affiliated with the U.S. government.