Medicare premiums are income-tested, and the test runs on old data. The premium year 2026 is priced off your 2024 tax return, and crossing an income line by a single dollar raises your Part B and Part D surcharges for the entire year. Enter your filing status, your 2024 modified adjusted gross income, and what your drug plan charges, and this calculator shows which of the six CMS brackets you land in, what your total monthly Medicare bill becomes, and how much income room remains before the next cliff.
IRMAA, the Income-Related Monthly Adjustment Amount, is the surcharge high earners pay on top of Medicare's base premiums. By statute the standard Part B premium covers about 25 percent of the program's projected cost per enrollee, with general federal revenue covering the rest; the top IRMAA tier covers about 85 percent. CMS estimated the surcharge reaches roughly 8 percent of Part B enrollees in 2026. Two details make it expensive in practice. It is a flat dollar amount that steps up at fixed income lines, so marginal income near a line is penalized far more than the bracket percentage suggests. And it stacks: a Part B surcharge and a Part D surcharge apply side by side, per person.
The table below is the official 2026 scale from the CMS fact sheet released November 14, 2025, built from 2024 MAGI. Bracket edges read as greater-than up to and including: MAGI of exactly $109,000 pays the standard premium for a single filer, and $109,001 pays the first surcharge.
| 2024 MAGI, single | 2024 MAGI, joint | Part B total | Part B surcharge | Part D surcharge |
|---|---|---|---|---|
| ≤ $109,000 | ≤ $218,000 | $202.90 | $0.00 | $0.00 |
| $109,001 – $137,000 | $218,001 – $274,000 | $284.10 | $81.20 | $14.50 |
| $137,001 – $171,000 | $274,001 – $342,000 | $405.80 | $202.90 | $37.50 |
| $171,001 – $205,000 | $342,001 – $410,000 | $527.50 | $324.60 | $60.40 |
| $205,001 – $499,999 | $410,001 – $749,999 | $649.20 | $446.30 | $83.30 |
| ≥ $500,000 | ≥ $750,000 | $689.90 | $487.00 | $91.00 |
Source: CMS, 2026 Medicare Parts A & B Premiums and Deductibles fact sheet, November 14, 2025. The Part D column is the surcharge only; your drug plan's own premium is separate and varies by plan. The standard 2026 Part B deductible is $283 for everyone regardless of income.
Variables in plain terms. MAGI is your adjusted gross income plus tax-exempt interest, read off the tax return from two years earlier. IRMAAB and IRMAAD are the flat surcharges from the table above, set by SSA and collected through Medicare. The drug plan premium is the one number on this page that is not universal; it depends on the plan you enrolled in. The headroom line is the practical output: it tells you how much room you have before the next cliff, which is exactly the number you need when deciding whether a Roth conversion, a capital gain, or a bonus fits under the wire.
The default profile is a single filer with 2024 MAGI of $145,000 and a drug plan costing $40 a month. That MAGI sits in the $137,001 to $171,000 bracket, so the Part B surcharge is $202.90 and the Part B total is $405.80 a month. The Part D surcharge adds $37.50, the plan adds $40.00, and the total Medicare bill lands at $483.30 a month, or $5,799.60 a year. A standard-premium neighbor with MAGI under $109,000 pays $242.90 all-in on the same $40 plan, so the bracket costs this filer an extra $240.40 a month, $2,884.80 a year. There is $26,000 of headroom left before the next line at $171,000.
The cliff cuts both ways at the first line. A single filer at exactly $109,000 pays $202.90 for Part B and no Part D surcharge. One dollar more moves the bill to $284.10 plus $14.50, an increase of $95.70 a month and $1,148.40 a year for that single dollar of income. Nothing about the tax on that dollar comes close, which is why IRMAA planning is mostly about knowing where the lines are.
Your 2026 premiums come from your 2024 return, and your 2026 income will set your 2028 premiums. SSA redetermines the tier every fall from the newest return on file, so a high-income year follows you for two premium years. The escape hatch is Form SSA-44. If a life-changing event dropped your income, retirement, a marriage or divorce, the death of a spouse, a work stoppage, or a large loss of investment income, you can ask SSA to re-tier you using your projected current-year income instead. Moving to a cheaper area, a market crash, or plain frugality do not qualify; the event list on the form is closed.
Each beneficiary pays their own IRMAA, even on a joint return. Take a married couple filing jointly with MAGI of $300,000, which lands in the $274,001 to $342,000 bracket. Each spouse enrolled in Part B pays $405.80 a month, so the household pays $811.60 a month for Part B alone, before drug coverage. The joint bracket doubles rather than splits. The exception is transitions: a divorce or the death of a spouse is a life-changing event that lets SSA re-tier the survivor off the joint return's income going forward.
Married couples who file separately face a different, much harsher scale. In 2026 the standard $202.90 premium applies only up to MAGI of $109,000; above that and below $391,000 the premium jumps to $649.20, and at $391,000 or more it is $689.90, per CMS figures. There is no gradual ladder between the two lines. For most couples living together, filing jointly is decisively cheaper.
Because MAGI is AGI plus tax-exempt interest, only AGI-reducing moves help. Pre-tax 401(k) and traditional IRA contributions, HSA contributions, and FSA elections lower AGI and can hold you under a line. Municipal bond interest is famous for being tax-free, but SSA adds it right back in, so it never buys headroom. Roth conversions work in the opposite direction: they raise AGI by the converted amount, and thanks to the lookback a conversion taken this year is already priced into your 2028 premiums, while one taken in 2024 is baked into this year's bill. The Roth vs Traditional IRA calculator covers the conversion trade-off in detail. Charitable giving through a donor-advised fund bunches deductions without changing MAGI much, so it is a weak IRMAA lever compared with the charitable giving tax calculator's income-tax angle.
If your premium tier is being set by wages rather than investments, the take-home pay calculator shows how pre-tax deferrals shrink the AGI that SSA reads. When you transition from employer coverage to Medicare, your Social Security claiming decision interacts with these premiums too, since Part B is deducted from the benefit estimated by the Social Security estimator. And once you are past 65 and drawing both checks, the retirement withdrawal calculator helps you pace portfolio withdrawals, which matter here because they push MAGI toward the bracket lines above.
IRMAA stands for Income-Related Monthly Adjustment Amount. It is a flat dollar surcharge added to Medicare Part B and Part D premiums once your modified adjusted gross income crosses a bracket line. CMS estimates it affects roughly 8 percent of people with Part B. The standard premium covers about 25 percent of Part B's cost per enrollee; the top IRMAA tier covers about 85 percent. The surcharge is set by SSA from your tax return and collected by Medicare, and it is a step function, not a percentage: one dollar of income over a line raises the whole surcharge for the entire year.
Your 2026 premiums are set from your 2024 tax return, a two-year lookback. SSA uses modified adjusted gross income, which is your adjusted gross income on Form 1040 line 11 plus tax-exempt interest from line 2a. If your income has dropped since then because you retired, divorced, lost a spouse, or stopped working, you can file Form SSA-44 to ask SSA to use your more recent, lower income instead. Otherwise the older return stands, and every year SSA redetermines the tier from the newest return on file.
Yes. Each Medicare beneficiary pays their own premium and their own surcharge, even on a joint tax return. A married couple with a joint MAGI of $300,000 lands in the $274,001 to $342,000 tier, and if both spouses are enrolled in Part B, each pays $405.80 a month in 2026, $811.60 combined. The one exception is the marriage or divorce itself: those are life-changing events that can trigger a Form SSA-44 appeal to re-tier the affected spouse off the joint return's income.
Yes. IRMAA is not tied to Original Medicare. Everyone enrolled in Part B pays the income-based Part B premium, including Medicare Advantage members, and the Part D surcharge applies to the drug coverage attached to Medicare Advantage plans too. A zero-premium Advantage plan does not escape either surcharge. The Part D IRMAA is paid to Medicare, never to your drug plan, and it is deducted from your Social Security check or billed directly if you are not yet drawing benefits.
MAGI is adjusted gross income plus tax-exempt interest, so pre-tax deferrals work and tax-exempt bonds do not. Contributions to a traditional 401(k), a traditional IRA within deduction limits, an HSA, or an FSA all reduce AGI and can pull you under a bracket line. Municipal bond interest is tax-free for income tax but still counts in MAGI, so it does not help. Roth conversions raise AGI and can push you into a higher tier, so the two-year lookback means a conversion in 2024 is already priced into your 2026 premium and one taken this year sets your 2028 premiums.
Married-filing-separately beneficiaries face the harshest scale of the three filing statuses. In 2026, a MAGI of $109,000 or less still pays the standard $202.90 Part B premium, but above that line and below $391,000 the premium jumps straight to $649.20 a month, and at $391,000 or more it is $689.90. There is no gradual climb between $109,000 and $391,000 the way there is for single and joint filers. If you are married and living together, filing jointly is almost always the cheaper IRMAA route.
All calculation logic on this page is implemented from the primary documents below. Each one is listed with the figure it supplies, so any rate or threshold in the result can be traced back to its published source.
Benefit rules and cost assumptions stated on the page, not implied.