Know what your federal job is really worth.

How FERS actually works

Federal retirement isn't a pension. It's a three-legged stool: a defined-benefit annuity from your federal service, the Thrift Savings Plan with up to a 5% government match, and Social Security. Each leg matters, and most online calculators only model one of them. The annuity gets the spotlight because it's the most distinctive piece — almost nobody in the private sector still has a real pension — but for a typical career fed, the TSP match and Social Security combined will equal or exceed the annuity's lifetime value.

The calculator above models all three legs together so you can see what your federal job is actually worth in retirement, not just the annuity slice. Source documents that govern these rules: the OPM CSRS/FERS Handbook and 5 U.S.C. Chapter 84.

The annuity formula (and the SCE kink most calculators miss)

For standard FERS employees the formula is 1% × years of service × high-3 average salary. If you retire at age 62 or later with at least 20 years of service, the multiplier bumps to 1.1% — that 0.1% sounds small but it's a 10% pension boost for the rest of your life. Worth working an extra year if it gets you across both thresholds.

Special Category Employees (federal law enforcement, firefighters, air traffic controllers, certain others) use a richer formula: 1.7% per year for the first 20 years, then 1.0% per year after. The kink at year 20 is what most generic calculators get wrong. An SCE who works 25 years doesn't get 1.7% × 25 = 42.5%. They get 1.7% × 20 + 1.0% × 5 = 39%. The first 20 SCE years are gold; everything after is at the standard rate.

Your high-3 is the average of your highest 36 consecutive months of basic pay — almost always your final three years. Locality pay counts. Awards, bonuses, and overtime don't. Reference: 5 U.S.C. § 8415.

When you can retire — and the trap most feds walk into

Standard FERS

Standard FERS has four immediate-retirement paths:

• MRA + 30: Minimum Retirement Age (56-57 depending on birth year) with 30+ years.
• Age 60 + 20: 60 with at least 20 years.
• Age 62 + 5: 62 with at least 5 years.
• MRA + 10: Reduced annuity — permanent 5% reduction for every year you're under 62. Usually deferred to 62 to avoid the reduction (the “postponed” option).

FERS Law Enforcement & other SCE

Federal LEOs, firefighters, air traffic controllers, certain customs/border roles, members of Congress, and congressional employees fall under the Special Category Employee provisions. The eligibility rules are different — and earlier — under 5 U.S.C. § 8412(d):

• Age 50 + 20: Age 50 with at least 20 years of SCE service.
• Any age + 25: Any age with at least 25 years of SCE service.

Two things SCE-specific that change the calculus from standard FERS:

• Mandatory separation. Federal LEOs and firefighters are required to separate by age 57 under 5 U.S.C. § 8425; ATCs by age 56. Limited waiver provisions exist but most SCE feds plan around the mandatory date rather than against it.
• A much longer RAS bridge. The Retiree Annuity Supplement runs from your retirement date until age 62 regardless of which provision you retire under. An SCE who retires at 50 collects 12 years of RAS — substantially more bridge income than a standard FERS retiree who retires at MRA + 30.

Both standard FERS and SCE also have a deferred path (separate before eligibility, claim at 62 with 5+ years vested). SCE doesn't really need the postponed option since the early-retirement provisions are already richer. More on choosing your date →

The trap: people read “Age 62 + 5” and assume they're set. But claiming an annuity at 62 with only 5-10 years of service means a tiny check — 11% (with the 1.1% bump) of high-3 at 10 years, before the spousal reduction. A 30-year career fed retiring at MRA replaces roughly 30% of pre-retirement income from the annuity alone. Eligibility doesn't mean adequacy. MRA + 10 vs. age 62 deep dive →

The Retiree Annuity Supplement — the bridge nobody explains right

If you retire under MRA + 30, age 60 + 20, or qualifying SCE provisions, you get a Retiree Annuity Supplement (RAS) — sometimes called the FERS Supplement or the Special Retirement Supplement. It approximates what your Social Security benefit would be at 62, paid monthly from your retirement date until the month you turn 62. It is not Social Security, and it is not calculated using your full work history — only your federal service years count.

Two things people miss constantly:

• The RAS is subject to the Social Security earnings test. Earn over the annual limit ($23,400 in 2025) from a post-retirement W-2 or self-employment job and your supplement gets reduced $1 for every $2 over the limit. Pension and TSP withdrawals don't count toward the earnings test — only earned income.
• The RAS ends the month you turn 62, regardless of whether you actually file for Social Security. There's no smooth handoff. If you delay SS to 67 or 70 to maximize the benefit (often the right move), you have a five-to-eight-year gap where the RAS check stops and the SS check hasn't started. Plan the cash flow.

MRA + 10 retirees do not get the supplement. Deferred retirees do not get the supplement. This is one of the strongest arguments against MRA + 10 over an immediate retirement under one of the qualifying provisions.

High-3 mechanics — why end-of-career promotions matter disproportionately

Your high-3 is averaged over your highest 36 consecutive months of basic pay. For most people, that's the last three years before retirement. Pin a step or a grade promotion in that window and it inflates the average — and therefore your pension — for the rest of your life.

The math: a 30-year fed earning $140K base who pins a $160K-base grade in the last three years has a high-3 of roughly $153K (with WGI step bumps interpolated). At 1% × 30 years × $153K, the annuity is about $46K/year. Same fed who never gets the late promotion: high-3 around $145K, annuity about $43.5K. That $2,500/year difference, COLA-adjusted across a 25-year retirement, compounds to roughly $90K in total lifetime pension dollars from a single late-career step.

Practical implication: declining a stretch assignment in your last three years to coast costs real money. The 1% (or 1.7%) multiplier per year is fixed by statute; the high-3 is the variable you can actually move. Same logic in reverse — taking a downgrade in your final three years (say, a step-down to a lower-stress role) directly reduces your lifetime pension.

The TSP match you'd leave behind

The federal government matches your TSP contributions up to 5% of basic pay: 1% automatic agency contribution (whether you contribute or not) plus a tiered match on the first 5% you put in (dollar-for-dollar on the first 3%, fifty cents on the next 2%). Stop contributing — or separate from federal service — and you stop receiving that money. The 5% match isn't advertised as part of your salary, but it's real compensation.

For a GS-13 mid-career fed earning around $110K base, the match is roughly $5,500/year. Continue contributing for another 20 years at a 7% blended return and that match alone — not including your own contributions — is worth about $240,000 at retirement. That's money you walk away from the moment you separate.

People weighing private-sector offers usually compare base salaries and miss this. A $130K private job that doesn't match isn't actually a $20K bump over a $110K federal job — it's a wash on direct comp before counting the pension. With the pension, the federal job typically wins by 15-25% in true present value. Full TSP mechanics →

FEHB into retirement — the most underrated benefit

If you've been enrolled in the Federal Employees Health Benefits program for the five years immediately before retirement (or the entire period of your federal service if shorter), you can carry FEHB into retirement at the same plans, the same network, and the same government share of premium — for the rest of your life. The government continues to pay roughly 72% of premium in retirement, just like in active service.

For a family plan running ~$650/month total, the government share is ~$465/month, or about $5,600/year of subsidized benefit, every single year of retirement. Lifetime value for a married couple retiring at 60 and living to 85: roughly $140,000 in present value. Most retirement calculators don't quantify this. The one above does.

The five-year rule has no exceptions and no waivers. Drop FEHB at any point inside that five-year window and you forfeit the carry-into-retirement option. Stay enrolled — even at the cheapest plan tier — through that final stretch. FEHB plan-selection guide →

Comparing FERS to a private-sector offer

The temptation when looking at outside offers is to compare gross salary against gross salary. Garbage comparison. The honest math is:

• Federal: base salary + locality + 5% TSP match + accrued pension value (~10-15% of salary equivalent for SCE, ~6-8% for standard FERS) + FEHB lifetime carry (~$5K/year for family) + leave accrual + step increases + the unpriced value of practical job security.
• Private: salary + 401(k) match (typically 3-4%) + employer health share (highly variable, almost always less than FEHB) + bonus and equity (variable, often illusory once vesting and tax are accounted for) + zero pension.

Even before the pension, federal total comp is usually 15-25% richer than the headline salary. The pension itself adds another 10-15% of annual salary in present value. A nominal $20K “raise” to leave is often a real-dollar pay cut — sometimes substantially so.

That said, federal jobs aren't for everyone. Private-sector roles can offer faster comp ramping, equity upside, more career mobility, and freedom from the slow grinding pace of government. The right comparison isn't apples-to-apples on the paycheck — it's lifetime compensation plus the quality-of-life factors you actually care about. The calculator above does the math; the rest is your call.

What this calculator does (and doesn't)

You enter your current age, federal salary, years of service, and planned retirement date — and the calculator returns a present-value estimate of your remaining federal compensation alongside an apples-to-apples comparison against any outside offer you punch in. Free-tier features include scenarios you can save and compare, TSP match projections, and COLA modeling. Account-holders also get year-by-year retirement income projections, FEHB lifetime value, breakeven salary calculations, and a downloadable PDF report.

What this calculator is not: a replacement for an official OPM benefit estimate, a personalized financial plan, or tax advice. It models the standard FERS rules and doesn't handle CSRS, CSRS Offset, FERS-RAE, or FERS-FRAE special variants. For irrevocable retirement decisions, get an official benefit statement from your HR shop and consider talking to a federal-benefits-aware financial planner.