FERS disability retirement calculator: how the annuity is figured
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By the OnPAR Federal Retirement Education editorial team · Last updated
Related: How FERS disability retirement works · What is the high-3? · FERS pension calculator · VA disability and FERS
Short answer: If you are under age 62 and not otherwise eligible to retire under 5 U.S.C. 8412(a)–(f) (see 5 CFR 844.304 — for most employees that means 62/5, 60/20, or MRA/30), OPM generally pays 60% of your high-3 for the first 12 months (minus 100% of any Social Security benefit you are entitled to that month), then 40% of your high-3 after that (minus 60% of Social Security disability), until age 62 — or your earned annuity if it is larger. At 62 the benefit is recomputed as if you had worked to the day before your 62nd birthday. You need at least 18 months of FERS civilian service and must apply for Social Security disability. MRA+10 alone (8412(g)) is not auto-classified as earned-only here because 844.304 cites only 8412(a)–(f); confirm with OPM. [1][2][5] This page is a worksheet with labeled example numbers — not an official OPM decision.
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Eligibility checklist (OPM)
- At least 18 months of federal civilian service creditable under FERS[1][4]
- You became disabled by disease or injury while in a FERS-covered job and cannot render useful and efficient service in your current position[1]
- The disability is expected to last at least one year from your application date[1]
- Your agency certifies it cannot accommodate you and has considered vacant same-grade/pay jobs in the same commuting area[1]
- You apply before separation or within one year after[1]
- You must apply for Social Security disability. If that application is withdrawn, OPM dismisses the FERS disability claim[1]
Full overview: How FERS disability retirement works.
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How OPM computes the disability annuity
OPM’s computation page uses different formulas depending on age and whether you already qualify for an immediate voluntary retirement.[2] The controlling regulation for the earned-only path is 5 CFR 844.304, which points to 5 U.S.C. 8412(a)–(f) or age 62 — not MRA+10 (8412(g)).[5][6]
| Your situation | What OPM pays |
|---|---|
| Age 62+ at disability retirement, or you meet 5 U.S.C. 8412(a)–(f) (for most employees: 62/5, 60/20, or MRA/30) — see 5 CFR 844.304 | Earned annuity only: 1% of high-3 × years of service (1.1% if age 62+ with 20+ years)[2][5] |
| Under 62 and not in the 844.304 earned-only group (includes MRA+10-only pending OPM confirmation) — first 12 months | 60% of high-3 minus 100% of any Social Security benefit for months you are entitled (or earned annuity if larger)[2] |
| Same group — after the first 12 months until age 62 | 40% of high-3 minus 60% of Social Security disability (or earned annuity if larger)[2] |
| When you reach age 62 | Recomputed as if you worked until the day before 62: service includes time on disability; high-3 is increased by FERS COLAs paid while disabled; then 1% (or 1.1% if total service ≥20 years)[2][3] |
There is generally no FERS retiree annuity supplement on a disability retirement. Survivor reductions (10% full / 5% partial) still apply if elected. OPM’s disability-reductions list does not include the regular MRA+10 age reduction (5 U.S.C. 8415(h)); this worksheet does not apply that cut to disability illustrations.[2][7]
Interactive worksheet (illustration only)
Enter made-up or approximate numbers. Answer the earned-only eligibility question. Results follow published OPM percentages and 5 CFR 844.304; they are not an official estimate and do not include the age-62 recompute, COLAs, survivor reductions, or special-provision (LEO/FF) factors.
MRA comes from OPM’s birth-year table (55 to 57). Default 57 is for birth year 1970 or later.[4]
What counts for earned-only disability math: 5 CFR 844.304 uses 5 U.S.C. 8412(a)–(f) — for most employees that means 62 with 5, 60 with 20, or MRA with 30 (special LEO/FF/ATC rules are not modeled here).[5][6] MRA+10 alone (8412(g)) is not treated as earned-only in this worksheet — under 62 you get a conservative dual illustration and an OPM-review banner; we do not apply the regular MRA+10 age reduction to disability results.[5][7] Not counted: deferred retirement; early optional/discontinued-service alone. Confirm unusual cases with OPM.[2][4]
Worked example (labeled, made-up numbers)
Assume high-3 $90,000, 5 years of service, and Social Security disability of $22,000 a year. Under 62 and not in the 844.304 earned-only group:[2]
- Year 1: 60% × $90,000 = $54,000 − $22,000 = $32,000/year (~$2,667/month). Earned floor = 1% × $90,000 × 5 = $4,500, so the 60% formula wins.
- After year 1: 40% × $90,000 = $36,000 − (60% × $22,000 = $13,200) = $22,800/year (~$1,900/month).
- At 62: OPM adds disability time to service and increases high-3 by FERS COLAs paid while disabled, then applies 1% or 1.1%. Exact dollars depend on your COLA history — see OPM’s computation page.[2]
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Questions and answers
How many months of service do I need for FERS disability?
OPM lists 18 months of creditable FERS civilian service (any age).[1][4]
Do I have to apply for Social Security disability?
Yes. A FERS disability application requires an SSDI application. If the SSDI application is withdrawn, OPM dismisses the FERS claim.[1]
Does MRA+10 alone put me on the earned-only disability path?
OPM’s website lists MRA+10 as an immediate voluntary retirement option and says earned-only applies if you meet immediate voluntary age/service.[2] But 5 CFR 844.304 expressly cites 5 U.S.C. 8412(a)–(f) (or age 62) — and MRA+10 is 8412(g).[5][6] This worksheet does not auto-apply earned-only for MRA+10 alone and does not apply the 8415(h) age reduction to disability figures. Confirm with OPM.
What happens at age 62?
If you retired on disability under 62 (and were not already on an earned immediate annuity), OPM recomputes the annuity as if you had continued working until the day before age 62.[2][3]
Official sources
- OPM: Types of Retirement (FERS disability eligibility)
- OPM: FERS Computation (disability formulas)
- OPM FAQ: Disability benefits and retirement
- OPM: FERS Eligibility (disability = any age / 18 months)
- 5 CFR 844.304: Disability annuity if otherwise eligible to retire (8412(a)–(f) or age 62)
- 5 U.S.C. 8412: Immediate retirement (MRA+10 is subsection (g))
- 5 U.S.C. 8415: Basic annuity computation (MRA+10 age reduction is 8415(h) for 8412(g)/8413(b))
Checked against OPM, TSP.gov and SSA on November 7, 2026. Education only, not legal, tax or financial advice. Your own situation may differ: check with OPM, the TSP, SSA or a tax professional. Not affiliated with OPM, the TSP, SSA or any government agency.