How federal retirement income is taxed: the 2026 complete guide

1. The six income streams and why each is taxed differently

A federal retiree’s monthly income is more complex than most private-sector retirees’ income — and the tax treatment of each piece is different. Most newly-retired federal employees don’t realize this until their first year of retirement, when their tax bill arrives 15 to 30 percent higher than they expected.

Here are the six income streams a federal retiree can receive, and how each is taxed at the federal level:

Consider a typical FERS retiree with a $40,000 pension + $24,000 Social Security + $20,000 TSP withdrawals + $12,000 FERS Supplement = $96,000 in gross retirement income. The federal tax on this combination depends heavily on the mix:

• If most income comes from Traditional TSP and FERS pension: essentially all $96,000 is taxable, producing federal tax of roughly $8,500-$9,500 after the standard deduction.
• If a significant portion comes from Roth TSP: the tax-free portion reduces the federal bill substantially — potentially by $2,000-$5,000 annually.
• If Social Security is the largest piece: the provisional income calculation produces tax treatment that varies dramatically based on other income levels.

The mix matters enormously. Two federal retirees with identical $96,000 gross retirement income can face federal tax bills that differ by $5,000-$8,000 annually depending on how the income is distributed across the six sources. Understanding the mechanics is the first step toward optimizing the mix.

2. How the FERS and CSRS pension are actually taxed

The FERS and CSRS pension are both taxed at the federal level as ordinary income — meaning they’re added to your AGI and taxed at your marginal bracket. But a portion of each monthly payment is tax-free, representing the after-tax contributions you made during your career.

The mechanics — the Simplified Method. The IRS requires federal retirees who began their annuity after November 18, 1996, to use the Simplified Method to calculate the tax-free portion. OPM does this calculation for you and reports the result on your annual 1099-R. Box 1 shows the total annuity received. Box 2a shows the taxable portion. Box 5 shows the tax-free portion.

The formula behind the Simplified Method:

The “expected number of monthly payments” is determined by IRS tables based on your age (and your spouse’s age if you elected survivor benefits) at the time the annuity began. The tax-free portion is a fixed dollar amount — it does NOT increase with COLAs.

A worked example. A FERS retiree contributed $52,000 of after-tax salary to the FERS Retirement and Disability Fund over their career. They retired at age 56 with a 50% spousal survivor benefit, and their spouse is 54. The IRS expected-payments table for this combination shows 360 expected monthly payments.

If the retiree’s gross monthly FERS annuity is $3,600 ($43,200/year):

• Tax-free portion: $144.44/month × 12 = $1,733/year
• Taxable portion: $43,200 − $1,733 = $41,467/year

The tax-free $1,733 continues each year as a fixed amount, even as the annuity itself grows with FERS COLAs. Once the retiree has recovered their full $52,000 in tax-free distributions (after approximately 30 years), the entire annuity becomes 100% taxable.

FERS vs CSRS difference. CSRS employees typically contributed substantially more after-tax salary than FERS employees (7% of salary vs FERS’s much smaller percentage). As a result, CSRS retirees usually have a larger tax-free monthly amount and a slightly lower effective tax rate on their pension than FERS retirees with similar gross income. The difference is meaningful but not enormous — typically 1-3 percentage points of effective rate.

State taxation varies substantially. Some states (Illinois, Mississippi, Pennsylvania, Alabama, Hawaii) fully exempt federal pensions from state income tax. Most states tax the federal pension as ordinary income at their normal state rates. Nine states (Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, Wyoming) have no state income tax at all, so the pension is tax-free at the state level by default. For the complete state-by-state breakdown, see the 9 tax-friendly states article.

3. The Social Security taxation cascade

The federal taxation of Social Security benefits is one of the most poorly-understood mechanics in retirement planning. The rules use a concept called provisional income (sometimes called “combined income”) that’s not used anywhere else in the tax code.

The provisional income formula:

The Social Security tax treatment depends on which of three tiers your provisional income falls into:

The key thing to understand: these thresholds have been frozen by statute since 1983 (the 50% tier) and 1993 (the 85% tier). They have never been adjusted for inflation. In 1983, a $25,000 single threshold was equivalent to roughly $80,000 in 2026 dollars. The thresholds have effectively shrunk by 70% in real terms — meaning more retirees are subject to Social Security taxation each year, even at modest income levels.

A worked example. A federal retiree files single with a $40,000 taxable FERS pension, $20,000 in Traditional TSP withdrawals, and $24,000 in Social Security:

This places the retiree well above the $34,000 single threshold for the 85% tier. Up to 85% of their Social Security ($24,000 × 85% = $20,400) is federally taxable.

The provisional income mechanic also produces the “tax torpedo” effect: at certain income levels, each additional dollar of pension or TSP income makes additional Social Security taxable simultaneously, producing effective marginal rates of 35-40% even for retirees in the nominal 22% bracket. The torpedo zone is particularly painful for middle-income federal retirees with substantial Traditional TSP balances.

The Social Security thresholds were last set in 1993. In real purchasing power, the $25,000 single threshold is equivalent to about $80,000 in 2026 dollars. The thresholds have effectively shrunk by 70% — meaning more federal retirees are subject to Social Security taxation each year, even at modest income levels.

4. Traditional TSP versus Roth TSP at withdrawal

The TSP is the third pillar of every federal retiree’s income. How withdrawals are taxed depends entirely on which balance you draw from.

Traditional TSP withdrawals. Every dollar you withdraw from your Traditional TSP balance is 100% federally taxable as ordinary income. This includes both the contributions you made (which were pre-tax during your working years) and the growth on those contributions. Traditional TSP withdrawals also count fully toward your AGI for purposes of the Social Security provisional income calculation, the IRMAA Medicare premium surcharge thresholds, state income tax (where applicable), and the $6,000 OBBBA senior bonus deduction phase-out. A $30,000 Traditional TSP withdrawal in 2026 increases your taxable income by $30,000 dollar-for-dollar.

Roth TSP qualified withdrawals. Every dollar you withdraw from your Roth TSP balance is federally tax-free, provided you meet two conditions:

1. The 5-year rule: Your Roth TSP account must have been open for at least 5 years (counted from January 1 of the year of your first Roth contribution).
2. Age 59½ or qualifying event: You must be age 59½ or older, OR meet a qualifying exception (disability, death of account holder, etc.).

If both conditions are met, Roth TSP withdrawals don’t count toward AGI, provisional income for Social Security, IRMAA thresholds, or state income tax. They’re invisible to virtually every income-based threshold in the tax code.

The SECURE 2.0 change to Roth TSP RMDs. Effective January 1, 2024, Roth TSP balances no longer have RMDs during the original account holder’s lifetime. Combined with the tax-free nature of qualified Roth withdrawals, this makes Roth TSP one of the most powerful tax-planning vehicles available to federal employees. A federal retiree with substantial Roth TSP balance can defer drawing it indefinitely, growing the balance tax-free, and pass it to heirs with favorable tax treatment. (For the RMD mechanics in full, see the 25% RMD penalty guide.)

The strategic implication. Federal employees who contribute the same dollar amount to Roth TSP vs Traditional TSP during their working years are making fundamentally different bets on their retirement tax bracket:

• Traditional contribution wins if: Your retirement marginal bracket will be lower than your working-year bracket
• Roth contribution wins if: Your retirement marginal bracket will be higher than your working-year bracket
• Roth also wins if: You want to minimize IRMAA exposure, manage Social Security taxation, leave tax-free money to heirs, or maintain flexibility on withdrawal timing

For federal employees in their working years, the Roth/Traditional decision deserves serious analysis. For federal retirees already with substantial Traditional balances, Roth conversions during the low-income window between retirement and Social Security/RMDs is the primary path to convert Traditional dollars to Roth treatment.

5. The FERS Annuity Supplement and its earnings test

The FERS Annuity Supplement (also called the Special Retirement Supplement, or SRS) is unique to federal retirement. It approximates the Social Security benefit you would receive at age 62, paid by OPM until you actually reach 62. It exists because FERS employees can retire as early as their Minimum Retirement Age (typically 56-57), but Social Security doesn’t start until 62 at the earliest.

Federal tax treatment: The FERS Annuity Supplement is 100% taxable as ordinary income at the federal level. It’s reported on the same 1099-R as your FERS basic annuity, with no after-tax basis component (you didn’t contribute after-tax dollars specifically to fund the supplement). It counts fully toward your AGI for all purposes.

The earnings test. The FERS Supplement is subject to a Social Security-style earnings test. If you earn wages or self-employment income above the annual limit, your Supplement is reduced by $1 for every $2 you earn over the limit.

• 2026 earnings test limit: $24,480
• Reduction formula: $1 reduction in Supplement per $2 in earnings above the limit

A worked example. A federal retiree receives a $12,000 annual FERS Supplement. They take a part-time consulting job paying $40,000/year:

The retiree’s effective hit from taking the $40,000 job: $7,760 in reduced Supplement, plus the federal income tax on the wage income itself, plus any state tax. For some retirees, the net after-tax benefit of post-retirement work is dramatically lower than the gross wage suggests.

Important exclusions from the earnings test: the FERS pension itself, Social Security benefits (once you start receiving them), Traditional or Roth TSP withdrawals, IRA withdrawals, investment income (dividends, interest, capital gains), and rental income (in most cases). The earnings test applies only to wages and self-employment income. Many federal retirees can structure post-retirement income through investments or business arrangements not classified as self-employment to avoid triggering the test.

The reporting mechanic. Each spring (typically May), OPM mails a survey to all FERS Supplement recipients asking them to report their prior-year earnings. The Supplement is adjusted retroactively if the survey shows earnings above the limit. Failure to respond to the survey can result in suspension of the Supplement. For federal retirees who take post-retirement work, this annual reconciliation is one of the most consequential paperwork events of the year.

6. The 2026 federal tax brackets applied to a federal retiree

Federal income tax on retirement income uses the same brackets as on working income — but the deductions and the income mix change the effective rates substantially.

2026 federal income tax brackets (from IRS Rev. Proc. 2025-32):

2026 standard deductions: Single $16,100; MFJ $32,200; Head of Household $24,150. Additional age 65+ deduction: $2,050 (single) / $1,650 each spouse (MFJ). New OBBBA senior bonus: $6,000 per person 65+ (phases out 6% per dollar above $75K single / $150K MFJ MAGI, fully gone at $175K / $250K).

Three stacked deductions for federal retirees 65+. A single federal retiree at age 66 in 2026 can claim the $16,100 standard deduction + $2,050 additional age 65+ deduction + $6,000 OBBBA senior bonus (if MAGI under $75K) = $24,150 total deductions before any taxable income is calculated. For an MFJ couple both 65+: $32,200 + ($1,650 × 2 = $3,300) + ($6,000 × 2 = $12,000) = $47,500 total deductions. The OBBBA senior bonus is meaningful but temporary — it applies to tax years 2025 through 2028 only, then sunsets unless Congress extends it.

A worked tax calculation. A single federal retiree age 66 in 2026 with a $40,000 FERS pension ($1,000 tax-free recovery via Simplified Method = $39,000 taxable), $24,000 Social Security ($20,400 taxable at 85% tier), a $15,000 Traditional TSP withdrawal (100% taxable), and a $5,000 Roth TSP withdrawal (0% taxable):

Tax calculation on the 2026 brackets: 10% on the first $12,400 = $1,240; 12% on the income from $12,401 to $50,250 (about $37,850) ≈ $4,542. Approximate total federal tax = $5,500-$5,800.

That’s an effective federal tax rate of roughly 6-7% on $84,000 gross retirement income — meaningfully lower than the marginal rate, thanks to the stacked deductions for retirees 65+. For most federal retirees, this is the structural reason that retirement tax bills are often lower than working-year tax bills despite similar gross income.

7. State-by-state treatment of federal retirement income

State taxation varies dramatically and can swing your total tax bill by $5,000-$15,000 annually depending on where you live. The major categories:

The no-income-tax states (Group 1) exempt all retirement income by default; note New Hampshire taxes interest/dividends only, phasing out by 2027. The fully-exempt states (Group 2) often produce better total outcomes than no-income-tax states because they typically pair the exemption with lower property tax burdens. Alabama and Hawaii (Group 3) exempt the FERS/CSRS pension specifically but still tax Traditional TSP and IRA withdrawals. The eight states that still tax Social Security (Group 4) mostly use income-based exemptions that protect lower- and middle-income retirees; West Virginia completed its phase-out as of the 2026 tax year. Everyone else (Group 5) taxes federal pension and TSP at standard rates.

The state tax decision is the single largest controllable variable in your federal retirement tax bill. For a comprehensive comparison and interactive calculator, see the 9 tax-friendly states article, which includes a state-by-state tool that calculates your specific tax burden based on your income mix.

8. Five questions federal retirees ask about taxation in 2026