FERS Supplement: How It Is Calculated, Who Gets It and When It Ends

OPM computes the supplement as if you were age 62 and fully insured for Social Security. It first estimates the Social Security benefit you would receive at 62 from a full 40-year career, then prorates that estimate by your years of FERS civilian service divided by 40. In shorthand: estimated age-62 Social Security benefit x FERS years of service / 40. OPM's actual computation uses your FERS earnings history and the Social Security benefit formula, so the shorthand shows the method rather than a personal estimate. Sources: OPM's FERS annuity supplement guidance and the OPM CSRS and FERS Handbook, Chapter 51.

OPM's own published example uses an estimated benefit of $1,000 per month and 30 years of FERS service: $1,000 x 30 / 40 = approximately $750 per month. The hypothetical illustration below uses the same method with a different, clearly labeled input.

Hypothetical illustration for education only, as of October 15, 2026. It is not a client result, a projection, or an estimate for any real person. Assume a federal employee with a $95,000 High-3 average salary and 30 years of creditable FERS service who retires at the minimum retirement age on an immediate, unreduced annuity.

Broadly, FERS employees who retire with an immediate and unreduced annuity before reaching 62. That typically means reaching your minimum retirement age with 30 years of service, or age 60 with 20 years. Employees whose annuity includes CSRS service generally also need at least one full calendar year of FERS service.

Certain special categories (law enforcement officers, firefighters, air traffic controllers) have their own rules and are generally eligible on retirement regardless of age, with different treatment of the earnings test until they reach their minimum retirement age.

People who take a deferred retirement, or who retire under MRA+10 with a reduction, generally do not receive it. OPM also states the supplement is not payable with a disability retirement.

If you take another job after retiring, earned income above an annual threshold reduces the supplement, on a formula similar to the Social Security earnings test. The test applies to the supplement only, not to your basic annuity. The reduction is $1 for every $2 of wages and net self-employment earnings above the exempt amount.

The current exempt amount: as of October 15, 2026, the Social Security Administration lists $24,480 for 2026 for people under full retirement age for the whole year (SSA, receiving benefits while working, SSA 2026 cost-of-living fact sheet). OPM's 2026 annual changes letter lists the same figure for FERS annuitants. The amount is indexed and changes each year, so check SSA and OPM for the year that applies to you.

When the reduction is applied: OPM tests earnings from the immediately preceding year, collected through an annual survey of annuitants who receive the supplement. The reduction therefore comes after the earning year ends, not as you earn, based on the prior year's earnings.

The important distinction: the test applies to earned income: wages and self-employment. It does not apply to your annuity, to portfolio withdrawals, to Roth conversion income, or to rental income. Retirees who plan a second career should model this before assuming both incomes arrive intact.

For law enforcement officers, firefighters, air traffic controllers and certain military reserve technicians, OPM guidance generally does not apply the test before the minimum retirement age. It can apply after that age.

OPM states the supplement generally stops at the end of the month before you turn 62. It is paid until the point you would be eligible for Social Security retirement benefits, and you are not required to apply for Social Security at 62 for the supplement to end on that schedule. See OPM's answer on whether the supplement continues after 62.

The supplement ends at 62. Many retirees treat that as a prompt to claim Social Security immediately, because that is when the bridge income stops.

That instinct is worth examining rather than following. Claiming at 62 permanently reduces your benefit, and the years between 62 and 70 are frequently the best Roth conversion window a federal retiree has. Bridging that gap from the portfolio instead, and converting while brackets are low, often produces a better lifetime result, particularly for the higher earner in a married couple. Outcomes depend on individual circumstances. For more on the claiming decision, see our guide on when to claim Social Security, and for the conversion window, Roth conversions for federal retirees.

This guide explains the method, but it does not estimate your supplement, and TradeWinds does not offer an online calculator or automated estimator for it. Your figure depends on your earnings record, your years of FERS service, and your retirement date. You can also see how the supplement fits alongside the basic annuity in our guide on how to calculate your FERS pension.

Book a 30-minute federal benefits review for a personalized estimate of your supplement alongside your pension, TSP, and Social Security timing.