What this calculator does
Find out whether your income means you'll pay extra for Medicare, and how much. Most people pay the standard Part B premium. If your income is higher, Medicare adds a surcharge to Part B and Part D. That surcharge is called IRMAA, short for income-related monthly adjustment amount.
Enter your filing status and your income. The calculator finds your tier, shows your monthly and yearly cost, and tells you how far you are from the next limit. Medicare looks back two years, so 2026 premiums depend on your 2024 tax return.
Where it's used
Why this math matters outside the classroom:
- Couples planning. A retired couple with $300,000 of income adds $202.90 and $37.50, then doubles it to find $480.80 a month.
- Roth conversion timing. A retiree with $42,000 of room before the next tier keeps a Roth conversion under that amount for the year.
- Budget checks. A single retiree with $120,000 of income multiplies $95.70 by 12 and budgets $1,148.40 for the year.
- Home sale planning. A couple selling a home checks whether the taxable gain would push their income past a limit two years ahead.
How to use it
- Choose the filing status from your 2024 tax return.
- Enter your 2024 income: your adjusted gross income plus any tax-exempt interest.
- If you file jointly, say whether both of you are on Medicare.
- Read your extra cost, then check the table to see the limits around your income.
What the inputs mean
- Tax filing status for 2024
- Married people who file separately and lived together at any time in the year have their own table, with fewer and steeper tiers.
- Income for 2024 (AGI plus tax-exempt interest)
- Medicare calls this modified adjusted gross income, or MAGI. It's your adjusted gross income (AGI) from your tax return, plus tax-exempt interest. Both are on Form 1040.
Formula and method
income = adjusted gross income + tax-exempt interest Part B surcharge = Part B premium for your tier − standard premium monthly extra per person = Part B surcharge + Part D surcharge yearly extra = monthly extra × people on Medicare × 12
IRMAA works like a set of cliffs, not a slope. Your whole surcharge is set by the tier you land in. This is the part most people miss: going one dollar over a limit brings the full surcharge for the next tier.
That's why the amount of room you have left matters. A large withdrawal, a Roth conversion or a home sale can raise your income for one year. Two years later, that one year sets your premium.
Worked example
You and your spouse filed jointly for 2024 with income of $300,000. You're both on Medicare.
- Your income is over $274,000 and up to $342,000, so you're in tier 2 of 5.
- The Part B premium in that tier is $405.80, and the standard premium is $202.90.
- The Part B surcharge is $405.80 − $202.90 = $202.90.
- Add the Part D surcharge: $202.90 + $37.50 = $240.40 per person.
- Double it for both spouses: $240.40 × 2 = $480.80.
Result: You'd pay $480.80 extra each month, or $5,769.60 for the year. You have $42,000 of room before the next tier.
Understanding the result
A result of $0 means you pay the standard Part B premium and no Part D surcharge.
If you're close to a limit, small choices can matter. Moving a Roth conversion to another year, or splitting a large withdrawal across two years, might keep you in a lower tier. A tax professional can help you weigh that against your income tax.
Did your income drop after a life-changing event, such as retirement or the death of a spouse? You can ask Social Security to use a more recent year. The form is SSA-44.
Assumptions and limitations
- It uses the 2026 amounts published by the Social Security Administration and the Centers for Medicare & Medicaid Services (CMS).
- Premiums for 2026 use 2024 income. Social Security may use the year before that if 2024 isn't available.
- Each person on Medicare pays the surcharge. This assumes both have Part B and Part D when both are enrolled.
- This is an estimate. Social Security decides your actual amount and sends you a notice.
- It shows only the Part D surcharge. Your drug plan's own premium varies by plan and isn't included.
- It doesn't cover premium penalties for signing up late, or help programs for people with low incomes.
- It doesn't include people who are married, file separately and lived apart all year. They use the single column, so choose that option.
Frequently asked questions
What are the IRMAA brackets?
They're the income limits that set your Medicare surcharge. The table on this page lists the 2026 limits and premiums for each filing status.
Which year's income does Medicare use?
It looks back two years. Your 2026 premiums use your 2024 tax return, because that's the latest return the IRS can usually share when premiums are set.
Do both spouses pay IRMAA?
Yes, if both are on Medicare. A joint return sets the tier, and each person then pays that tier's surcharge. So a couple pays it twice.
Can I get IRMAA reduced?
You can ask Social Security to use a newer year if a life-changing event lowered your income. Examples include retiring, or the death of a spouse. Use Form SSA-44.
What happens if I go one dollar over a limit?
You pay the full surcharge for the next tier. The cost doesn't rise bit by bit, so that one dollar can add over $1,000 a year for a couple.
Sources
- Social Security POMS HI 01101.020: IRMAA sliding scale tables (checked 2026-10-31)
- CMS: 2026 Medicare Parts B premiums and deductibles (checked 2026-10-31)
How this calculator is checked
Method: SSA POMS HI 01101.020 and the CMS 2026 fact sheet, which agree on every figure compared. Figures live in src/lib/finance/medicare-2026.ts. The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-31. Found a problem? Tell us.
Embed this calculator
Put this IRMAA Calculator on your own website or blog for free. Paste this code where you want it to appear: