About Medicare IRMAA
IRMAA stands for Income-Related Monthly Adjustment Amount. It is a surcharge that higher-income Medicare beneficiaries pay on top of the standard Part B and Part D premiums. The Social Security Administration sets IRMAA each year using your modified adjusted gross income (MAGI) from the tax return two years earlier, so your 2026 surcharge is based on your 2024 income. Roughly the top 7 to 8 percent of Medicare enrollees pay it.
The MAGI that triggers IRMAA is your adjusted gross income (Form 1040 line 11) plus any tax-exempt interest (line 2a). That add-back of municipal-bond interest catches many retirees by surprise. In 2026 the surcharge begins above $109,000 for a single filer and $218,000 for a married couple filing jointly, then climbs through five tiers. At the top tier a single beneficiary pays an extra $487.00 a month for Part B and $91.00 for Part D, about $6,936 a year above the standard premiums.
How it works
IRMAA is a cliff, not a gradual phase-in. Cross a threshold by a single dollar and the entire higher surcharge applies for the whole year. The calculation is a lookup, not a percentage:
MAGI = AGI (1040 line 11) + tax-exempt interest (line 2a) Look up MAGI in the 2026 bracket table for your filing status Annual IRMAA = (Part B surcharge + Part D surcharge) x 12 Standard 2026 Part B premium = $202.90/month (no IRMAA) Top tier total Part B = $689.90/month (surcharge $487.00)
- Two-year lookback: 2026 IRMAA uses 2024 MAGI, the most recent return the IRS has shared with SSA.
- Per-person, not per-household: a married couple where both are on Medicare each pay their own IRMAA.
- Part D surcharge is paid to Medicare, even though you buy the Part D plan from a private insurer.
Worked example
A single retiree had $145,000 of MAGI on their 2024 return (including $5,000 of municipal-bond interest). What is their 2026 IRMAA?
- MAGI: $145,000, which falls in the third single bracket ($137,000.01 to $171,000).
- Part B surcharge: total Part B becomes $405.80, which is $202.90 surcharge over the $202.90 base.
- Part D surcharge: $37.50 per month.
- Monthly IRMAA: $202.90 + $37.50 = $240.40.
- Annual IRMAA: $240.40 x 12 = $2,884.80 on top of standard premiums.
2026 IRMAA brackets (single filers)
Based on 2024 MAGI. Married-filing-jointly thresholds are double the single amounts ($218,000 / $274,000 / $342,000 / $410,000 / $750,000).
| 2024 MAGI (single) | Total Part B / mo | Part D surcharge / mo | Annual IRMAA |
|---|---|---|---|
| $109,000 or less | $202.90 | $0 | $0 |
| $109,001 to $137,000 | $284.10 | +$14.50 | ~$1,164 |
| $137,001 to $171,000 | $405.80 | +$37.50 | ~$2,885 |
| $171,001 to $205,000 | $527.50 | +$60.40 | ~$4,618 |
| $205,001 to $499,999 | $649.20 | +$83.30 | ~$6,351 |
| $500,000 or more | $689.90 | +$91.00 | ~$6,936 |
Strategies to stay under the cliffs
Because IRMAA is a cliff and runs on a two-year lag, the practical defense is to manage the MAGI on the return you file two years before you turn 65 or two years before any year you want a lower surcharge. The most common levers:
- Roth conversions before Medicare: convert traditional IRA balances in your late 50s and early 60s so the taxable income lands before the IRMAA lookback window begins, leaving lower required distributions later.
- Qualified charitable distributions (QCDs): after age 70 and a half, sending up to $108,000 (2025 limit, inflation-indexed) of IRA money straight to charity satisfies your RMD without adding to MAGI.
- Harvest gains in low-income years: realize capital gains in a year your MAGI is already well below a threshold, rather than bunching them into a year that tips you over.
- Watch one-time events: a home sale, inherited IRA distribution, or large bonus two years out can trigger a surcharge; spread the income across tax years where possible.
Common pitfalls
- Forgetting tax-exempt interest. Municipal-bond interest is added back into IRMAA MAGI, so it can push you over a cliff even though it is income-tax-free.
- One-time income spikes. A Roth conversion, large capital gain, or property sale in 2024 raises 2026 IRMAA, even if your ongoing income is modest.
- Not appealing after a life event. Retirement, divorce, death of a spouse, or loss of pension income lets you file form SSA-44 to use a more recent, lower income.
- Treating it as a marginal rate. IRMAA is a cliff: exceeding a threshold by $1 triggers the full tier, so the effective marginal cost near a bracket edge can be enormous.
- Ignoring the two-year lag. Plan income two years ahead; the surcharge you pay today reflects a return you already filed.
Related tools
Frequently asked questions
What is Medicare IRMAA?
IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge that higher-income Medicare beneficiaries pay on top of the standard Part B and Part D premiums. The Social Security Administration sets it each year from your modified adjusted gross income two years earlier, so 2026 IRMAA is based on your 2024 tax return.
What income counts toward IRMAA MAGI?
IRMAA MAGI is your adjusted gross income (Form 1040 line 11) plus tax-exempt interest (line 2a). The municipal-bond interest add-back is the part that surprises many retirees, because that interest is free of income tax but still counts toward the IRMAA threshold.
What are the 2026 IRMAA thresholds?
For 2026 the surcharge starts above $109,000 of MAGI for a single filer and $218,000 for a married couple filing jointly, both based on 2024 income. There are five surcharge tiers, with the top tier beginning at $500,000 single and $750,000 joint. The standard 2026 Part B premium with no IRMAA is $202.90 per month.
Why does crossing a bracket by $1 cost so much?
IRMAA is a cliff, not a gradual phase-in. The moment your MAGI exceeds a threshold, the full surcharge for that tier applies for the entire year. Going one dollar over a 2026 single bracket can add more than a thousand dollars in annual surcharges, which is why income near a bracket edge is worth managing carefully.
Can I appeal or reduce my IRMAA?
Yes. If a life-changing event lowered your income, such as retirement, marriage, divorce, death of a spouse, or loss of a pension, you can file form SSA-44 to have IRMAA recalculated on more recent income. You can also manage future IRMAA by timing Roth conversions, capital gains, and withdrawals to stay below the cliffs.