How Much Will My Social Security Be Reduced If I Have a CSRS Pension?

For individuals who have dedicated a portion of their careers to public service under the Civil Service Retirement System (CSRS), understanding how their federal pension might interact with Social Security benefits has been a complex concern. Historically, many federal employees under CSRS did not contribute to Social Security, leading to questions about potential benefit reductions. The Social Security Administration (SSA) had specific provisions designed to address situations where individuals received a pension from non-covered employment and also qualified for Social Security benefits.

Recent legislative changes have altered this landscape. The Social Security Fairness Act of 2023, signed into law on January 5, 2025, has effectively repealed both the Windfall Elimination Provision (WEP) and the Government Pension Offset (GPO). This means that for Social Security benefits payable for months after December 2023, these reductions no longer apply. While these provisions are no longer in effect, understanding their historical application can still provide insight into the rationale behind past benefit calculations and the impact they once had on many retirees.

Windfall Elimination Provision Explained

The Windfall Elimination Provision (WEP) was a Social Security rule that aimed to prevent what was considered an unfair advantage for individuals who spent a portion of their careers in jobs not covered by Social Security, such as those under CSRS, but also had sufficient earnings in Social Security-covered employment to qualify for benefits. Social Security’s benefit formula was weighted to provide a higher percentage of pre-retirement earnings to workers with lower lifetime average earnings. Without WEP, individuals who received a substantial non-covered pension could appear as low earners in Social Security’s system, potentially receiving a higher Social Security benefit than intended.

WEP applied to an individual’s own earned Social Security benefit, not to spousal or survivor benefits. It adjusted the way the Social Security Administration calculated the Primary Insurance Amount (PIA), which is the monthly benefit a worker receives at full retirement age. The standard PIA formula uses “bend points” and applies different percentages to portions of a worker’s average indexed monthly earnings (AIME). For example, for those turning age 62 in 2025, the first $1,226 of AIME would be multiplied by 90%, with lower percentages applied to higher earnings tiers.

WEP would reduce this first 90% factor to a lower percentage, often to 40% for those with 20 or fewer years of substantial earnings in Social Security-covered employment. The reduction in this factor was mitigated by the number of years an individual had substantial earnings under Social Security. If a person had between 21 and 29 years of substantial earnings, the 90% factor was reduced on a sliding scale, increasing by 5% for each year over 20. For instance, someone with 21 years of substantial earnings would have their first bend point factor reduced to 45%, and with 29 years, it would be 85%.

Individuals with 30 or more years of substantial earnings were exempt from the WEP reduction entirely, meaning their first bend point factor remained at 90%. The annual amount considered “substantial earnings” varied by year; in 2024, earnings of $31,275 were needed to count as a year of substantial earnings. The maximum monthly WEP reduction for 2025, had it still been in effect, would have been $613.

Government Pension Offset Explained

The Government Pension Offset (GPO) historically impacted Social Security benefits for individuals receiving a government pension from non-covered employment, such as a CSRS pension. Unlike WEP, which affected an individual’s own Social Security benefit, GPO applied to spousal or survivor Social Security benefits. Its purpose was to prevent a situation where a person could receive a full government pension and also a full Social Security spousal or survivor benefit, which might be seen as double-dipping compared to those whose primary work was covered by Social Security.

Under the GPO rule, any spousal or survivor Social Security benefit an individual was eligible for would be reduced by two-thirds of the amount of their non-covered government pension. For example, if a person received a CSRS pension of $1,200 per month and was eligible for a Social Security spousal benefit of $1,000, the GPO would reduce the Social Security benefit by $800 (two-thirds of $1,200). In this scenario, the Social Security spousal benefit would be reduced from $1,000 to $200 per month. If two-thirds of the pension exceeded the Social Security benefit, the Social Security benefit could be reduced to zero.

There were limited exceptions to the GPO. These generally applied if the government employment was covered by Social Security, or if the government pension was based on employment that ended before specific dates, typically before 1957 for federal employment. However, for most individuals with CSRS pensions, the GPO would have applied to any spousal or survivor Social Security benefits they were otherwise eligible to receive. The Government Pension Offset was repealed by the Social Security Fairness Act of 2023, effective for benefits payable from January 2024.

Calculating Your Estimated Benefit

With the repeal of the Windfall Elimination Provision (WEP) and the Government Pension Offset (GPO) for benefits payable after December 2023, the process of estimating your Social Security benefit when you also have a CSRS pension has become more straightforward. You no longer need to apply these specific reduction formulas. Understanding your earnings history and pension details remains important for an accurate assessment of your overall retirement income.

To estimate your Social Security benefit, you should first obtain your Social Security earnings record. This record details your taxed earnings over your career and can be accessed by creating an account on the Social Security Administration’s (SSA) “my Social Security” website. Reviewing this record helps confirm the earnings that will be used in your Social Security benefit calculation. Separately, you will need to know the amount of your CSRS pension, which can be found on statements from the Office of Personnel Management (OPM) or your pension administrator.

Since WEP and GPO no longer apply, your Social Security benefit will be calculated based on the standard formula. This takes into account your 35 highest-earning years in Social Security-covered employment to determine your Average Indexed Monthly Earnings (AIME). This AIME is then applied to the Social Security bend point formula (e.g., 90% of the first segment, 32% of the next, 15% of the remainder for 2025 eligibilities) to determine your Primary Insurance Amount (PIA). The SSA’s online benefit calculators can provide estimates based on your earnings record.

The Social Security Administration makes the final determination of your benefit amount. They will apply the current law to your earnings record and pension information. If you were previously subject to WEP or GPO, your benefits for months after December 2023 should be adjusted, and you may receive retroactive payments for 2024. For precise figures and to confirm the impact of the repeal on your specific situation, directly consulting the Social Security Administration is recommended.