Free irmaa medicare premium calculator
Enter your modified adjusted gross income and this IRMAA calculator estimates your total monthly Medicare Part B premium — the standard base plus any Income-Related Monthly Adjustment Amount surcharge your income triggers, updated live, as you type.
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Estimated only. Actual withholding depends on your W-4 elections, filing status, and local laws. Consult your payroll provider for exact figures.
Results are estimates. Consult a professional.
What is IRMAA, the Medicare income surcharge?
IRMAA — the Income-Related Monthly Adjustment Amount — is an extra charge added to your Medicare Part B and Part D premiums when your income is above a set threshold. This IRMAA calculator estimates your total monthly Part B premium, the standard base premium plus any surcharge your income triggers, so you can see what a high income costs you in Medicare.
Most people pay only the standard Part B premium. But about 8% of Medicare beneficiaries — those with higher modified adjusted gross income — pay more, because IRMAA adds a sliding-scale surcharge on top. The surcharge is a cliff, not a gradual phase-in: cross a bracket by a single dollar and the full surcharge for that tier applies to every month of the year.
How the Medicare IRMAA surcharge is calculated
Your total Part B premium is the standard base premium plus the IRMAA surcharge for your income bracket. The base is the same for everyone; the surcharge depends on which MAGI tier you land in and on your tax-filing status.
Two features trip people up. First, IRMAA is per-bracket, not marginal — unlike income tax, the whole surcharge for your tier applies, with nothing tapered. Second, the income that counts is your MAGI from two years ago, not this year's, because of the lookback rule covered below.
CMS — 2025 Medicare Parts A & B Premiums and Deductibles (standard Part B premium $185.00; deductible $257).The 2-year MAGI lookback explained
Medicare does not have your current income, so it uses the most recent tax return the IRS has shared — which is the return from two years earlier. Your 2025 IRMAA is based on the MAGI from your 2023 tax return. A one-off spike two years ago — a Roth conversion, a home sale, a large capital gain — can therefore raise your premium today even if your income has since dropped.
A worked example using the IRMAA calculator
James is a single filer with a modified adjusted gross income of $130,000. He wants to know his total monthly Part B premium including the IRMAA surcharge. This is the calculator's default input.
Step 1 — Find the bracket
A single MAGI of $130,000 falls into the calculator's second surcharge tier, which adds an IRMAA equal to the base premium itself.
Step 2 — Add base plus surcharge
2025 IRMAA brackets for Part B and Part D
These are the official 2025 IRMAA brackets from CMS and SSA, based on your 2023 MAGI. The Part B column is the total monthly premium (the $185.00 base plus the surcharge); the Part D column is the add-on you pay on top of your drug plan premium. The lowest row is the standard premium with no surcharge.
| MAGI — single | MAGI — married filing jointly | Total Part B / month | Part D add-on / month |
|---|---|---|---|
| $106,000 or less | $212,000 or less | $185.00 | $0.00 |
| over $106,000 to $133,000 | over $212,000 to $266,000 | $259.00 | $13.70 |
| over $133,000 to $167,000 | over $266,000 to $334,000 | $370.00 | $35.30 |
| over $167,000 to $200,000 | over $334,000 to $400,000 | $480.90 | $57.00 |
| over $200,000 to $500,000 | over $400,000 to $750,000 | $591.90 | $78.60 |
| $500,000 or more | $750,000 or more | $628.90 | $85.80 |
2025 brackets, based on 2023 MAGI. Source: CMS 2025 Part B fact sheet and SSA POMS HI 01101.020. The live calculator above currently uses 2024 figures.
SSA — POMS HI 01101.020, 2025 IRMAA sliding-scale tables (Part B totals and Part D add-ons).Who has to pay IRMAA?
IRMAA reaches roughly 8% of people with Medicare Part B — those whose income two years ago was above the first threshold. You are most likely to be affected if any of these apply:
- You are still working or have a high pension alongside Medicare.
- You took a large one-time gain two years ago — a Roth conversion, a property sale, or a big required minimum distribution.
- You have substantial investment or rental income, including the tax-exempt interest that MAGI adds back in.
- You are a higher-earning couple — the married-filing-jointly thresholds are double the single ones, but high combined income still crosses them.
Because the brackets are cliffs, careful timing of income — spreading a Roth conversion across years, or harvesting gains below a threshold — can keep you in a lower tier. The surcharge is recalculated every year against your latest available return, so a single high year affects only the corresponding premium year.
Common IRMAA mistakes and gotchas
- Treating the cliff like a tax bracket. One dollar over a threshold applies the full surcharge to all 12 months — it is not marginal. Crossing the first single threshold by $1 can cost roughly $888 in extra Part B premiums for the year.
- Forgetting tax-exempt interest. MAGI adds back municipal-bond interest, so income you thought was invisible can still push you into a higher tier.
- Overlooking Part D. The IRMAA add-on applies to drug coverage too, on top of Part B — the table above shows both.
- Not appealing a life-changing event. If your income dropped after the lookback year because you retired or lost a spouse, you can file Form SSA-44 to have the surcharge reduced — it will not happen automatically.
- Assuming it is permanent. IRMAA is reassessed yearly. If your income falls back below the threshold, the surcharge comes off two years later.
Accuracy, limitations, and sources
This calculator estimates your total monthly Medicare Part B premium from your modified adjusted gross income. It is an estimate, not financial or tax advice, and not an official Medicare determination. The live tool currently uses the 2024 standard Part B base and a simplified single-filer bracket set; the 2025 brackets in the table above — for both Part B and Part D, single and married — are the current official figures. The calculator does not apply the two-year lookback for you, does not compute Part D add-ons, and does not handle married-filing-separately rules. Confirm your own surcharge with Medicare or the Social Security Administration.
Because Part B premiums are deducted straight from your Social Security check, pair this with the Social Security calculator to see your benefit, and browse all retirement calculators or the full calculator directory.
CMS — 2025 Medicare Parts A & B Premiums and Deductibles.SSA — POMS HI 01101.020, IRMAA sliding-scale tables.Medicare.gov — Part B costs and how income affects your premium.Frequently asked questions about the free irmaa medicare premium calculator
About this IRMAA Medicare premium calculator
This IRMAA calculator runs entirely in your browser — nothing you enter is sent anywhere. It estimates your total monthly Medicare Part B premium by adding the Income-Related Monthly Adjustment Amount surcharge for your income bracket to the standard base premium. The surcharge is a cliff, not a marginal rate: crossing a threshold by a dollar applies the full tier surcharge. It is an estimate, not an official Medicare determination.
Because Part B premiums are deducted straight from your Social Security check, pair it with the Social Security calculator to see your benefit. Browse more retirement calculators or the full calculator directory.