CSRS Retirement Calculator

The CSRS stepped multiplier in practice

CSRS uses a tiered formula that accelerates in the early years. The first five years of creditable service earn 1.5% per year. Years 6 through 10 earn 1.75% per year. Year 11 and beyond earn 2.0% per year. The 80% cap stops accruals once you've hit that ceiling.

On a $90,000 high-3 salary, the math looks like this: years 1-5 produce 7.5% (5 x 1.5%), years 6-10 add 8.75% (5 x 1.75%), and each year after 10 adds 2.0%. At 30 years of service, the total replacement rate is 56.25%. At 40 years, it's 76.25%. You need roughly 41.5 years to hit the 80% ceiling.

Unused sick leave converts to additional creditable service at the rate of 2,087 hours per year. A federal employee who retires with 2,000 hours of sick leave gets an extra 11.5 months of service credit. That doesn't sound like much, but at $90,000 high-3 and 30 years, an extra 11.5 months adds roughly $1,725/year to the annual pension for life.

CSRS vs. FERS: what the numbers actually show

A CSRS employee with 30 years and a $90,000 high-3 gets approximately $50,625/year from pension alone (56.25% of $90,000). A FERS employee with identical tenure and salary gets $27,000/year from the pension (30%), but also receives Social Security (potentially $20,000-$25,000/year depending on their earnings history) and has accumulated TSP savings with a 5% agency match for 30 years. The total retirement income for FERS can be comparable or exceed CSRS depending on how much TSP they accumulated.

Where CSRS clearly wins over a long retirement: the COLA. CSRS retirees receive the full CPI-W increase every year with no cap. FERS retirees under age 62 receive no COLA at all, and after 62, if CPI exceeds 3%, they get CPI minus 1 percentage point. In a year with 5% inflation, CSRS retirees get 5% and FERS retirees get 4%. That 1-point gap compounds over 25 years of retirement into a meaningful purchasing power difference.

The high-3 average salary

CSRS uses the same high-3 definition as FERS: the average of your three consecutive highest years of basic pay. Basic pay includes locality pay but excludes overtime, bonuses, cash awards, and allowances. It doesn't have to be your final three years; it's the three-year window in your career with the highest average.

For most CSRS employees, the high-3 will be the last three years before retirement since federal salaries generally trend upward. But if you took a downgrade at some point or moved to a lower-grade position, your high-3 might be from several years back. OPM calculates it when you apply. You can verify it yourself by pulling your SF-50s for each year of service.

CSRS Offset: the hybrid most people don't understand

Some federal employees are in CSRS Offset rather than straight CSRS. This applies to people who were rehired after 1983 into positions where they'd previously been under CSRS. CSRS Offset employees pay Social Security taxes and participate in Social Security, but their CSRS pension is reduced (offset) by whatever Social Security benefit they earned from federal service once they become eligible for SS at age 62.

The pension formula under CSRS Offset is identical to regular CSRS: the same stepped multiplier, the same 80% cap, the same high-3 calculation. The difference is that at age 62, if you're eligible for Social Security, your CSRS pension is reduced by the SS benefit attributable to your CSRS Offset years. Net income stays roughly the same (pension drops, SS starts), but the source changes.

CSRS Offset employees need to understand both the CSRS formula and the Social Security formula to project their full retirement income accurately. The WEP calculator also matters here: any Social Security benefit from outside employment was historically subject to the Windfall Elimination Provision, though WEP was repealed in January 2025.

Retirement eligibility under CSRS

CSRS has three standard retirement paths. Age 55 with 30 or more years of service is the most common. Age 60 with 20 or more years. Age 62 with at least 5 years. Unlike FERS, there's no MRA+10 reduced-annuity option, and the age thresholds don't change based on birth year.

Voluntary Early Retirement Authority (VERA) allows CSRS employees to retire at age 50 with 20 years of service, or at any age with 25 years, when their agency offers an early out. VERA availability depends on the agency, not the employee. Your human resources office will notify eligible employees when VERA is on the table.

There's no equivalent of the FERS MRA+10 reduced annuity under CSRS. If you leave federal service before meeting a retirement eligibility threshold, you either take a refund of your contributions or leave them in to qualify for a deferred retirement at the earliest eligible age. Deferred CSRS retirees begin receiving benefits at the age at which they would have been eligible (typically 62 with 5 years, or whatever threshold they'd eventually meet).

Voluntary contributions

CSRS allows voluntary contributions beyond the mandatory 7-8% withholding, up to 10% of your total basic pay earned during your federal career. These extra contributions earn interest (currently 2% compounded annually) and can be used to purchase a supplemental annuity at retirement or withdrawn as a lump sum. They're separate from TSP.

The voluntary contribution account is one of the more obscure CSRS features. Few employees use it, but for someone late in their career looking for a last-mile retirement boost, it's worth asking OPM or your agency's benefits officer about.

Frequently asked questions