Is Your FERS Pension Taxable? The Annuity Exclusion Explained

Most of your FERS annuity is taxable federal income — but there is a small, often-overlooked tax-free portion built into every monthly payment. If you've been withholding tax on your full pension, you may be overpaying. This guide explains exactly why the exclusion exists, how the IRS Simplified Method calculates it, and what the real dollar impact looks like for different FERS contribution tiers.

Why FERS Creates a Tax-Free Basis

A federal employee's pension is funded from two streams: a large agency contribution (which you never paid tax on) and a smaller employee contribution (which you did). The tax law recognizes this: you can't be taxed twice on money you already paid tax on, so the IRS allows you to recover your after-tax employee contributions tax-free.¹

Your FERS employee contribution rate depends on when you were hired:²

These contributions are withheld from your paycheck, but unlike your TSP pre-tax contributions, they do not reduce your federal taxable wages. Your W-2 Box 1 reflects full salary as if the FERS deduction didn't happen for income tax purposes. So you paid income tax on those dollars — and you're entitled to get them back tax-free in retirement.

How Much Basis Do You Have?

Your cumulative after-tax FERS contributions depend on your salary history and hire date. At a rough average of $85,000/year over 30 years:

These are rough estimates for planning purposes. Your actual basis comes from your OPM retirement award letter or Form CSA 1099-R Box 9b, which OPM mails each January.

The IRS Simplified Method

For any FERS annuity that started after November 18, 1996, you must use the IRS Simplified Method to calculate the tax-free portion of each payment.³ The General Rule (actuarial tables) is not permitted for government pensions on this rule.

The formula is straightforward:

Table 1 — Expected Monthly Payments (Single Life)

The expected number of payments is set by your age on your annuity starting date — not current age. This number comes directly from IRS Publication 575, Table 1:³

Note: if your annuity covers joint lives (you and a survivor), use Table 2 from Publication 575 instead — the expected payments are higher because the payment stream may continue to a surviving spouse. Table 2 is based on combined ages at annuity start.

Key Rule: Exclusion Ends When Basis Is Recovered

Your monthly exclusion continues only until your total after-tax contributions are fully recovered. After that, your entire monthly payment is taxable — even if you live 30+ more years. Congress established this rule in 1986 (prior to that, exclusions continued indefinitely).

The recovery period equals exactly your expected-payment divisor. A retiree who starts benefits at 57 (310 divisor) finishes recovering their basis 25.8 years after retirement — at age 82.8 on average.

Two Worked Examples

Example A: FERS Original (0.8%), Retires at 57

Maria hired in 1995, average salary $90,000, contributed 0.8% for 30 years. Total after-tax contributions: approximately $21,600. Monthly pension: $3,240.

• Age at first payment: 57 → Table 1 divisor: 310
• Monthly exclusion: $21,600 ÷ 310 = $69.68/month tax-free
• Taxable portion: $3,240 − $69.68 = $3,170.32/month
• Tax-free percentage: ~2.1%
• Recovery complete: after 310 months (~age 82.8), full pension becomes taxable

For Maria at a 22% federal bracket, the monthly exclusion saves roughly $15/month in federal taxes. That's $180/year and cumulative $4,700 over the 26-year recovery window — modest but real, and many retirees miss it entirely.

Example B: FERS-FRAE (4.4%), Retires at 60

David hired in 2016, average salary $95,000, contributed 4.4% for 20 years. Total after-tax contributions: approximately $83,600. Monthly pension: $2,090.

• Age at first payment: 60 → Table 1 divisor: 260
• Monthly exclusion: $83,600 ÷ 260 = $321.54/month tax-free
• Taxable portion: $2,090 − $321.54 = $1,768.46/month
• Tax-free percentage: ~15.4%
• Recovery complete: after 260 months (~age 81.7)

David's larger basis under the FRAE 4.4% tier produces a meaningful exclusion — at 22% bracket, he saves roughly $71/month ($852/year) in federal tax. Over 21.7 years, that totals roughly $18,500 in cumulative tax savings.

How to Find Your Exact Cost Basis

You need your total after-tax contributions to apply the Simplified Method. Three ways to get the number:

1. OPM Retirement Award Letter

When OPM processes your retirement, they mail a civil action number package that includes a statement of your total employee contributions. This is the most reliable source — use this number for your first year's tax return.

2. Form CSA 1099-R, Box 9b

Starting in the first January after you retire, OPM sends an annual 1099-R. Box 9b is labeled "Total employee contributions." This is the cumulative after-tax amount you contributed throughout your career. Enter this on Worksheet A of the 1040 instructions (Simplified Method Worksheet) to calculate your annual exclusion.⁴

3. Check Your Leave and Earnings Statements

Your LES shows the FERS deduction each pay period. If you have access to your history in MyPay or through your agency HR, you can add them up — but OPM's 1099-R is more reliable and easier.

CSRS Comparison: Much Larger Exclusion

CSRS employees contributed 7% of pay — roughly 9× the FERS-original rate. A CSRS employee who averaged $90,000 over 35 years accumulated approximately $220,500 in after-tax contributions. At retirement age 62 (Table 1 divisor 260), that produces a monthly exclusion of $848/month — a significant portion of a typical $4,000–$6,000/month CSRS annuity. CSRS retirees should especially not skip this calculation.¹

TSP and Social Security: A Different Tax Picture

While your FERS pension has a small tax-free component, your other two retirement pillars are taxed differently:

Traditional TSP withdrawals are 100% taxable as ordinary income — no exclusion applies, because your TSP contributions were made pre-tax (box 1 wages were reduced). The IRS has never seen those dollars. See the TSP withdrawal options guide for how distribution elections affect withholding.

Roth TSP withdrawals are tax-free (contributions and earnings) provided you are at least 59½ and the 5-year rule is satisfied. No income tax, no exclusion calculation needed. See the Roth vs. Traditional TSP guide.

Social Security is 0–85% taxable depending on your provisional income (MAGI + half of SS). At typical FERS retirement income levels, most retirees end up with 50–85% of their Social Security subject to tax. The federal employee Social Security guide covers the provisional income threshold math.

IRMAA: Your Combined Income in Retirement Matters

Whether you take your full FERS pension exclusion or not, the taxable portion of your pension (plus TSP withdrawals and Social Security) flows into your MAGI for IRMAA purposes. The 2026 IRMAA first tier is $109,000 for single filers — a threshold that FERS pension + TSP distributions can approach for many retirees in their peak-withdrawal years. Plan Roth conversions accordingly during the gap window between early retirement and RMD onset. See the FEHB and IRMAA planning guide for the full 2026 threshold table and the TSP Roth conversion calculator for sizing annual conversions.

FERS Pension Tax Exclusion Calculator

Enter your total after-tax FERS contributions (from OPM award letter or 1099-R Box 9b), your age at first annuity payment, and your monthly pension to see your monthly exclusion, tax savings, and when your basis runs out.

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