Retirement Income Tax Calculator (2026)
Most retirement tax estimates miss two things: the Social Security taxation cascade and the new OBBBA senior deduction. This calculator handles both. Enter your income sources to see your estimated federal tax bill, effective rate, and whether your income puts you at risk of Medicare IRMAA surcharges.
How this calculator works
Retirement has a fundamentally different tax structure than working years. Four features make this calculator different from a generic income tax estimator:
1. Social Security provisional income
Up to 85% of Social Security benefits become taxable ordinary income — but how much depends on your provisional income, which is calculated differently than AGI. Provisional income = all other income + 50% of your SS benefit. At low provisional incomes, SS is completely tax-free. As it rises, the taxable portion ratchets up in two steps.1
| Provisional income | SS taxable (single) | SS taxable (MFJ) |
|---|---|---|
| Below $25K / $32K | 0% | 0% |
| $25K–$34K / $32K–$44K | up to 50% | up to 50% |
| Above $34K / $44K | up to 85% | up to 85% |
Source: IRC §86. Thresholds are NOT adjusted for inflation — they've been frozen since 1983, which is why more retirees hit the 85% ceiling each year.
2. OBBBA senior deduction (new 2025–2028)
The One Big Beautiful Bill Act added a $6,000 per-person deduction for Americans age 65 and older — on top of the regular standard deduction. For a couple where both spouses are 65+, that's an extra $12,000 off taxable income.2
- Stacks on top of standard deduction ($32,200 MFJ / $16,100 single in 2026)
- Phases out at 6% of MAGI above $150,000 (MFJ) or $75,000 (single)
- Fully phased out at $250,000 (MFJ) or $175,000 (single)
- Available 2025–2028 only — it expires unless Congress extends it
- Does not reduce IRMAA Medicare surcharges (IRMAA is MAGI-based, not taxable-income-based)
3. Capital gains preferential rates
Long-term capital gains and qualified dividends are taxed at 0%, 15%, or 20% — not at ordinary income rates. The 0% rate applies to taxable income (including the LTCG) below $98,900 (MFJ) or $49,450 (single) in 2026.3 LTCG stacks on top of ordinary income for this calculation — which means ordinary income "uses up" the 0% window first.
4. IRMAA Medicare surcharge
If your MAGI (roughly, your AGI plus tax-exempt interest) exceeds $109,000 single / $218,000 MFJ, Medicare adds a surcharge to your Part B and Part D premiums. At Tier 1, that's an extra $974/year per person — $1,948/year per couple. And it's a cliff, not a ramp: one dollar over the threshold triggers the full-year surcharge.4
This calculator flags your IRMAA tier so you know whether Roth conversions, QCDs, or income timing moves are worth pursuing. See our Medicare IRMAA Planning Guide for the complete bracket table and avoidance strategies.
Go beyond the estimate — model your specific strategy
This calculator shows a static snapshot. A retirement income specialist runs the multi-year model: how your tax bill evolves as RMDs start, how Roth conversions shift the picture over a decade, which withdrawal sequence minimizes lifetime taxes, and whether your plan survives a surviving-spouse IRMAA cliff. They optimize for the whole retirement, not just year one.
Related tools and guides
- Roth Conversion Window Calculator — find how much you can convert each year without crossing IRMAA tiers or a higher bracket
- RMD Calculator 2026 — project your required minimum distributions and see their IRMAA and SS taxation impact
- Tax-Efficient Withdrawal Order — which accounts to tap first and why the conventional "taxable first" rule costs most retirees tens of thousands
- Medicare IRMAA Planning Guide — complete 2026 tier table, the RMD-IRMAA cascade, and 6 avoidance strategies
- Roth Conversion Window Guide — the pre-RMD bracket arbitrage opportunity explained with a worked couple example
- OBBBA Senior Deduction Guide — how the $6,000 deduction expands your Roth conversion window before it expires in 2028
- QCD Guide — how donating directly from your IRA reduces AGI (and therefore IRMAA and SS taxation) three ways at once
- IRC §86. "Inclusion in gross income of social security benefits." Provisional income thresholds: $25,000/$34,000 (single), $32,000/$44,000 (MFJ). Up to 85% of SS taxable at higher tier. Thresholds not inflation-adjusted. law.cornell.edu/uscode/text/26/86. Also: IRS Publication 915 (2025), "Social Security and Equivalent Railroad Retirement Benefits." IRS Pub 915.
- One Big Beautiful Bill Act (OBBBA), signed July 2025. New §63(c)(5)(B) — senior additional standard deduction: $6,000 per qualifying individual age 65+, available tax years 2025–2028. Phase-out: 6% of MAGI above $75,000 (single) / $150,000 (MFJ); fully phased out at $175,000 / $250,000. IRS 2026 inflation adjustments (OBBBA). Also: Tax Foundation analysis; Kitces.com OBBBA planning guidance.
- IRS Rev. Proc. 2025-61. 2026 capital gains tax rates. 0% rate: taxable income below $98,900 (MFJ) / $49,450 (single). 15% rate: up to $613,700 (MFJ) / $551,350 (single). 20% rate: above those thresholds. LTCG stacks on top of ordinary income for rate determination. IRS Rev. Proc. 2025-61.
- Centers for Medicare & Medicaid Services. "2026 Medicare Parts A & B Premiums and Deductibles." CMS Fact Sheet, November 2025. IRMAA Tier 1 threshold: $109,000 (single) / $218,000 (MFJ). Part B base: $202.90/month; Tier 1: $284.10/month (+$974/year per person). cms.gov. Also: IRS Rev. Proc. 2025-32 for 2026 tax bracket thresholds and standard deduction amounts.
This calculator estimates 2026 federal income tax only. It does not model: state income taxes, AMT, net investment income tax (NIIT), itemized deductions, tax-exempt municipal bond interest added back to IRMAA MAGI, self-employment tax, or Medicare premium calculations beyond IRMAA Tier classification. The single-filer 0% LTCG threshold ($49,450) is verified against IRS Rev. Proc. 2025-61. Social Security provisional income thresholds are from IRC §86 (not adjusted for inflation since 1983). Not tax or investment advice.