IRMAA is the income surcharge on Medicare Part B and Part D, and it bills you in 2026 based on what you earned in 2024. The brackets are cliffs: $1 over a line triggers the entire surcharge. Here is the full table, what counts as MAGI, and the moves that keep you off the ledge.
The Income-Related Monthly Adjustment Amount. Standard Medicare beneficiaries pay premiums covering about 25% of program costs; the government pays the rest. Higher-income beneficiaries pay a bigger share — 35%, 50%, 65%, 80%, or 85% — which works out to 1.4, 2.0, 2.6, 3.2, or 3.4 times the standard Part B premium, plus a fixed dollar surcharge on Part D. Fewer than 10% of Part B beneficiaries pay it, but the people it catches are often surprised: the first notice is usually a smaller Social Security deposit.
Social Security sets each year's IRMAA from the most recent tax return the IRS has on file. For 2026 premiums, that is the 2024 return you filed in 2025. The mechanics matter for planning: income you realize this year (2026) sets your 2028 premiums. There is no amending your way around it after the fact — once the coverage year starts, the surcharge stands unless a life-changing event qualifies for reconsideration.
| Single 2024 MAGI | Joint 2024 MAGI | Part B Rate | Part B Total/mo | Part D/mo | Annual Surcharge, Each |
|---|---|---|---|---|---|
| ≤ $109,000 | ≤ $218,000 | standard | $202.90 | $0 | $0 |
| ≤ $137,000 | ≤ $274,000 | 1.4× | $284.10 | $14.50 | $1,148.40 |
| ≤ $171,000 | ≤ $342,000 | 2.0× | $405.80 | $37.50 | $2,884.80 |
| ≤ $205,000 | ≤ $410,000 | 2.6× | $527.50 | $60.40 | $4,620.00 |
| < $500,000 | < $750,000 | 3.2× | $649.30 | $83.30 | $6,356.40 |
| ≥ $500,000 | ≥ $750,000 | 3.4× | $689.90 | $91.00 | $6,936.00 |
Source: CMS 2026 premium fact sheet. Married filing separately: standard up to $109,000, then 3.2× below $391,000 and 3.4× above — the middle tiers do not apply, which is why high-income MFS is the most expensive filing status per dollar of income. A married couple on Medicare pays every surcharge twice, so each bracket line costs the household double. The 2027 brackets (2025 MAGI) are projected to start near $112,000 single / $224,000 joint.
Enter your 2024 MAGI and filing status for the exact monthly surcharge, household annual total, and distance to the next cliff.
IRMAA Calculator →Start with adjusted gross income (line 11 of Form 1040) and add back tax-exempt interest from municipal bonds (line 2a). That is it. From there, the inclusions and exclusions decide most planning conversations:
The QCD point is the one most often missed: after age 70½, donating IRA money directly to charity satisfies RMD obligations without a dollar of MAGI, while writing a personal check and taking a charitable deduction gives with one hand and takes with the other.
The brackets do not phase in. Cross a line by a dollar and the whole surcharge applies for the entire coverage year. A single filer at exactly $171,000 of 2024 MAGI pays $240.40 a month in combined Part B and Part D surcharges — $2,884.80 a year. At $171,001 the tier flips to 2.6×: $385.00 a month, $4,620.00 a year. The marginal cost of that dollar is $1,735.20. Near a threshold, the game is worth playing hard: defer a bonus, shift a gain-harvesting sale, or trim a year-end Roth conversion by a few thousand dollars.
Required minimum distributions start at 73 and only grow. A retiree who retired at exactly the standard-bracket edge can get pushed over a cliff by nothing but RMD growth, because the distribution is ordinary income that cannot be declined. The levers: size Roth conversions in the gap years between retirement and RMD age to shrink the future traditional balance; use QCDs once eligible; and watch the bracket lines every fall when you can still act on the current year. The RMD calculator shows how fast your required withdrawal climbs — and flags the IRMAA interaction.
Yes, for a listed life-changing event: retirement or work reduction, death of a spouse, divorce, marriage, loss of income-producing property, or reduction of certain pension income. File Form SSA-44 with Social Security, attaching proof of the event and an estimate of your current-year income. This is how most new retirees kill a surcharge built on their last working year's salary. What does not qualify: investment losses in a normal market, deciding to take less income, or a one-time gain you regret. A temporary spike otherwise corrects itself one year later, when the lower-income return becomes the lookback year.
Modified adjusted gross income from two years back, pulled straight from your tax return by Social Security. MAGI here means AGI plus tax-exempt municipal bond interest. Notable exclusions: Roth qualified withdrawals, HSA withdrawals, loans, and the excluded portion of home sale gains. Notable inclusions: taxable Social Security benefits, capital gains, and Roth conversions in the year you do them.
Almost certainly IRMAA. If the income on your return from two years ago crossed a threshold, your Part B premium is multiplied by 1.4, 2.0, 2.6, 3.2, or 3.4 and a Part D surcharge stacks on top. In 2026 that starts at $109,000 single MAGI ($218,000 joint) and the first tier adds $95.70 a month per person.
The brackets are cliffs, not phase-ins. A single filer at exactly $171,000 of 2024 MAGI pays $240.40 a month in Part B plus Part D surcharges, $2,884.80 a year. At $171,001, the whole surcharge resets to the next tier: $385.00 a month, $4,620.00 a year. One dollar of MAGI, $1,735.20 of premium, which is why year-end Roth conversions get sized to stop just under a line.
Yes, if your income fell because of a qualifying life-changing event: retirement or work reduction, death of a spouse, divorce, marriage, loss of income-producing property, or reduction of certain pension income. File Form SSA-44 with Social Security with documentation of the event and your current income estimate. A market downturn alone does not qualify.
Yes, and this surprises people. IRMAA is recomputed every year from the newest two-year-old return. A one-time spike — a big capital gain year, a large Roth conversion, a retirement bonus — raises premiums for exactly one coverage year, then drops back automatically when the lower-income year becomes the lookback year. You do not need to appeal a temporary spike unless a life-changing event lets you.