Worked example — not a real case
Illustrative worked example. The household is hypothetical; every figure is computed by the same verified engines and rule packs the calculators use.
Worked example · updated 2026-07-30
FERS at MRA+10 vs Waiting Until 62 — What the 1.1% Multiplier Is Worth
An illustrative federal employee reaches the minimum retirement age at 57 with 25 years of service, and could instead work to 62 with 30 years. The same FERS formula runs both ways, showing the MRA+10 age reduction on one side and the 1.1% multiplier on the other.
The illustrative household
A hypothetical GS-13 born in 1970 has a high-3 average salary of $98,000 and 25 years of creditable service when they reach their minimum retirement age of 57. Staying five more years would take them to age 62 with 30 years. Both paths are computed below with the same OPM formula and the same verified rule pack.
Walkthrough
Step 1 — the formula does not change; three inputs do
The FERS basic annuity is high-3 average salary × years of creditable service × a multiplier. Nothing about that changes between the two paths. What changes is the service count (25 years versus 30), the multiplier that applies (1% versus 1.1%), and whether an age reduction is taken. Those three levers are the entire difference, and two of the three move in the same direction.
Step 2 — the MRA lookup, from the birth-year table
The minimum retirement age is set by birth year in 5 U.S.C. 8412(h): 55 for those born before 1948, rising in two-month steps to 56 for 1953–1964, then again to 57 for anyone born in 1970 or later. This employee's 1970 birth year lands on a flat MRA of 57 years and 0 months. The engine reads that from the verified fers-rules pack rather than assuming it.
Step 3 — MRA+10 carries a permanent age reduction
Retiring at the MRA with at least 10 but fewer than 30 years of service is allowed, but the annuity is permanently reduced by 5% for each year the retiree is under age 62 — 5/12 of 1% for every full month. At 57, that is 60 full months under 62, a 25% reduction that does not go away later. The unreduced figure is computed first, then the reduction is applied.
Step 4 — the 1.1% multiplier needs both conditions, not either
The multiplier rises from 1% to 1.1% only when the retiree is at least 62 at separation and has at least 20 years of creditable service. Both conditions, not one. The five extra years in this scenario satisfy the age condition and push service to 30, so the second path uses 1.1% on a larger service count with no reduction — three favourable changes stacking at once.
Step 5 — what the arithmetic produces
The computed result below runs both inputs through the same fersAnnuity engine used by the FERS retirement calculator on this site. The gap is not the 10% the multiplier change alone suggests, because the service years and the removed reduction compound with it. Note also that the MRA+10 path forgoes five years of salary and five years of TSP contributions and agency match — costs the annuity formula never sees.
What the engine returns
Computed at page render from the inputs above, by the same functions the calculator runs.
Annual annuity difference between the two paths
$13,965.00
$32,340.00 at 62 versus $18,375.00 at MRA+10
Show the math, step by step
- Path A · High-3 average salary
- $98,000.00
- Path A · Creditable service
- 25 years
- Path A · Multiplier
- 1% (standard)
- Path A · Unreduced annuity
- $98,000.00 × 25 × 1% = $24,500.00
- Path A · MRA+10 age reduction
- 60 months under age 62 × 5%/12 per month = 25% reduction
- Path A · Reduced annuity
- $24,500.00 × (1 − 25%) = $18,375.00
- Path A · Gross monthly annuity
- $18,375.00 ÷ 12 = $1,531.25
- Path B · High-3 average salary
- $98,000.00
- Path B · Creditable service
- 30 years
- Path B · Multiplier
- 1.1% (age 62+ with 20+ years of service)
- Path B · Unreduced annuity
- $98,000.00 × 30 × 1.1% = $32,340.00
- Path B · Gross monthly annuity
- $32,340.00 ÷ 12 = $2,695.00
Verified 2026-07-30 against OPM — FERS computation, eligibility, creditable service & annuitant pamphlet (effective 2026-01-01)
Estimate only — not legal, financial, or benefits advice. Only OPM can determine your actual benefit.
Official source: OPM — FERS annuity computation ↗
Takeaway
Between MRA+10 at 57 and an immediate retirement at 62, three levers move together: five more years of service, the 1.1% multiplier, and the removal of the 25% age reduction. That is why the difference is far larger than the multiplier change alone. Nothing here says which path is right for anyone — OPM's computation at retirement is the only figure that governs, and this is arithmetic, not a recommendation.
Now run your own numbers →
FERS Retirement Calculator
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The household on this page is hypothetical and is described as such throughout. Nothing here reports a real person, a real determination, or a real outcome, and no result on this site is a promise about any case. Estimates only — the agency named above makes every actual determination.