Applying for FERS Disability Retirement

FERS disability retirement is not a judgement about how ill you are in general. 5 U.S.C. § 8451(a)(1)(A) asks a narrower question: whether, because of disease or injury, you are unable to render useful and efficient service in the position you hold. Someone can be plainly capable of other work and still qualify, which is the part most applicants underestimate about their own case.

The eligibility bar is 18 months of creditable civilian service — far shorter than any other federal retirement — and then three procedural facts decide whether the application works at all.

1. There is a hard deadline, and it is short

Under 5 U.S.C. § 8453 the application goes to your agency while you are still employed, or to OPM within one year after separation. Miss that window and the entitlement is gone, however strong the medical case is. The exception is narrow: someone mentally incompetent at separation or within that year has the deadline measured from the restoration of competency.

This catches people who leave first and decide later. If disability retirement is even a possibility, file before the year runs — an application can be withdrawn, a missed deadline cannot be reopened.

2. You must also apply to Social Security

5 CFR 844.201(b) prevents OPM from authorising payment until you show either a filed SSDI application or a statement from SSA that you are not eligible to file. This is a procedural requirement rather than a medical one: you do not have to be approved for SSDI — the two programmes apply different tests, and being refused by SSA does not refuse you here — but the application has to exist.

Applicants who skip it because they expect an SSDI refusal find their FERS annuity held up over the missing receipt rather than over anything to do with their health.

3. The 60% is gross, and the offset can take all of it

§ 8452(a)(1) pays 60% of average pay for the first 12 months and 40% after that. Both are quoted everywhere; both are figures before the offset in § 8452(a)(2), which reduces the annuity by 100% of any SSDI benefit during the first 12 months and by 60% of it afterwards.

So the first year is the one that surprises people in the wrong direction: an SSDI award can leave the FERS annuity at nothing at all, and the retiree no better off than SSDI alone. The statute stops the reduction at zero — it never turns into a debt — but it can consume the whole payment.

Why the 40% phase usually never happens

§ 8452(d)(1) sets a floor: the annuity may not be less than the one your service has already earned under the ordinary formula. For anyone with a long career that floor is higher than 40% of high-3 less 60% of an SSDI benefit — so the headline 40% is replaced outright and never appears on their statement.

A 30-year employee has earned 30% of high-3 under the ordinary formula. Against a 40% phase that SSDI has already reduced, the earned annuity is frequently the larger of the two, and it is the one that gets paid.

What happens at 62, and the part nobody expects

§ 8452(b) recomputes the annuity the day before your 62nd birthday, under the ordinary § 8415 formula, with two adjustments in your favour: every month spent on the disability roll counts as creditable service, and your average pay is increased by every cost-of-living adjustment paid in the interim.

That first adjustment is worth more than it sounds. Someone who leaves at 45 with 15 years of service arrives at the recomputation with about 32 — which is past the 20-year test, so the accrual factor rises to 1.1% on the whole of it. And it is worth noting that the recomputation can still come out lower than the phase it replaces; it is a redetermination, not a guarantee of an increase.

One more thing runs in a disability retiree’s favour throughout: the age-62 freeze on cost-of-living adjustments does not apply. § 8462(c)(3) reaches annuities under §§ 8412, 8413 and 8414, and a disability annuity is paid under § 8452 — so it is adjusted for inflation from the start, while an ordinary retiree under 62 is not.

What this guide does not cover

Nothing here is about the medical evidence, which is what applications actually turn on, or about the agency’s obligation to consider reassignment before supporting one. It also does not cover the periodic earnings and medical reviews that continue after an award, or the rules that end an annuity when someone is restored to earning capacity. Those are decisions on a file, not arithmetic.

Sources

• 5 U.S.C. § 8451 — eligibility, including the 18-month service requirement and the “useful and efficient service” test. Text of § 8451
• 5 U.S.C. § 8452 — the 60/40 formula, the Social Security offset, the earned-annuity floor at (d)(1), and the recomputation at 62. Text of § 8452
• 5 U.S.C. § 8453 — the application, and the one-year deadline after separation. Text of § 8453
• OPM CSRS/FERS Handbook, Chapter 60 — Disability Retirement. Chapter 60 (PDF)

The annuity arithmetic behind this guide is in lib/fers-disability.js. This is a calculation site rather than a legal one: for the application itself, an agency retirement specialist and — where a case is contested — a lawyer who practises before the MSPB are the right people to ask.

This guide is informational only. It is not financial, tax, or legal advice, and FedAnnuity is not affiliated with OPM or the U.S. government. Retirement rules turn on the specific facts of a career, and only your agency and OPM can give you a binding figure.

Last reviewed: August 2026 · Against 5 U.S.C. §§ 8451, 8452 and 8453, and 5 CFR 844.201.