Medicare IRMAA Brackets: 2026 Part B and Part D
2026-09-27
Short answer: For 2026, the standard Medicare Part B premium is $202.90 per month. IRMAA begins when the income used by Social Security exceeds $109,000 for an individual return or $218,000 for a joint return. The first IRMAA tier adds $81.20 per month to Part B and $14.50 per month to Part D. That first step is $95.70 a month, or $1,148.40 over 12 months.
The 2026 IRMAA figures
For 2026, the standard Part B premium is $202.90 per month. The income-related monthly adjustment amount, or IRMAA, is layered on top when the income Social Security uses crosses a threshold.
| 2024 MAGI used for 2026 premiums | Individual return | Joint return | Part B IRMAA | Part D IRMAA |
|---|---|---|---|---|
| Base tier | $109,000 or less | $218,000 or less | $0 | $0 |
| Tier 1 | over 109,000 to 137,000 | over 218,000 to 274,000 | $81.20/mo | $14.50/mo |
| Tier 2 | over 137,000 to 171,000 | over 274,000 to 342,000 | $202.90/mo | $37.50/mo |
| Tier 3 | over 171,000 to 205,000 | over 342,000 to 410,000 | $324.60/mo | $60.40/mo |
| Tier 4 | over 205,000 to under 500,000 | over 410,000 to under 750,000 | $446.30/mo | $83.30/mo |
| Top tier | $500,000 or more | $750,000 or more | $487.00/mo | $91.00/mo |
Social Security generally bases the 2026 determination on the federal tax return filed in 2025 for tax year 2024. That lag is why a current retirement budget can be affected by older income.
The formula
annual IRMAA increase = 12 × (monthly Part B IRMAA + monthly Part D IRMAA)The Part D number above is only the IRMAA surcharge. Your actual Part D plan premium is separate.
Worked example: crossing the first tier
Compare the base tier with Tier 1 for 2026.
- Added Part B amount: $81.20 per month.
- Added Part D amount: $14.50 per month.
- Combined monthly increase:
81.20 +14.50 = $95.70. - Annualized:
95.70 × 12 =1,148.40.
The important arithmetic is not merely the income tax on the last dollar of MAGI. Crossing an IRMAA threshold can also change Medicare premiums for the year to which that determination applies.
Why it behaves like a cliff
Within a tier, the published IRMAA amount is fixed. A small amount of MAGI above a threshold can therefore trigger the same monthly adjustment as a much larger amount of MAGI within that tier. That does not mean the extra income was a mistake; it means the Medicare premium effect belongs in the comparison.
The mistake people make: looking only at this year’s income
IRMAA has a lookback. A retiree can reduce current income and still receive an income-related premium because Social Security is using an earlier federal tax return. That timing matters around retirement, Roth conversions, large capital gains, and property sales. It also means a one-time income spike can affect Medicare premiums later even when the cash event is over. Some qualifying life-changing events can support a request for a new determination, but the adjustment is not automatic. When comparing a Roth conversion or asset sale, put the possible Medicare premium effect on the same timeline as the tax effect instead of assuming the premium follows the transaction immediately.
What would flip the answer
- Your filing status changes. Joint-return thresholds are different from individual thresholds.
- Social Security accepts a reconsideration. Certain life-changing events may allow a more recent income figure to be used.
- Your MAGI stays inside the same tier. Additional income that does not cross the next line does not create another IRMAA step.
- Your filing, income, timing, or eligibility facts change. Re-run the calculation with the facts for the year you are actually filing or planning.
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