Medicare IRMAA Calculator
IRMAA (the income-related monthly adjustment amount) is a surcharge added to your Medicare Part B and Part D premiums when your income is above a set level. This calculator shows your 2026 Part B premium and your Part B and Part D surcharges. Enter your modified adjusted gross income (MAGI) and filing status. IRMAA uses your MAGI from two years earlier (2024 for 2026). The 2026 Part B base premium is $202.90/month; the highest earners pay $689.90/month plus a $91.00 Part D surcharge. All figures are sourced from the CMS 2026 fact sheet and verified for 2026.
A single filer with $150,000 MAGI is in IRMAA tier 3: a Part B premium of $405.80 plus a $37.50 Part D surcharge, $240.40 extra per month ($2,884.80/year).
2026 Medicare IRMAA brackets
| Single MAGI | Joint MAGI | Part B premium | Part D surcharge |
|---|---|---|---|
| $0 to $109,000 | $0 to $218,000 | $202.90 | $0.00 |
| $109,000 to $137,000 | $218,000 to $274,000 | $284.10 | $14.50 |
| $137,000 to $171,000 | $274,000 to $342,000 | $405.80 | $37.50 |
| $171,000 to $205,000 | $342,000 to $410,000 | $527.50 | $60.40 |
| $205,000 to $500,000 | $410,000 to $750,000 | $649.20 | $83.30 |
| Over $500,000 | Over $750,000 | $689.90 | $91.00 |
Married filing separately (lived with spouse): $109,000 or less = $202.90; up to $391,000 = $649.20; above = $689.90. Source: CMS.
Why your 2024 income sets your 2026 surcharge
IRMAA trips up more retirees than almost any other Medicare figure, and the reason is timing: your 2026 surcharge is set by your modified adjusted gross income from 2024, the most recent tax return the IRS has passed to Social Security. A one-time event two years ago (selling a house, converting a traditional IRA to a Roth, taking a large capital gain) can push you over a threshold long after the money is spent. The first bracket begins at $109,000 for a single filer and $218,000 for a couple filing jointly, and the brackets behave as cliffs, not ramps: one dollar of MAGI over a line moves you into the next tier for the whole year, adding both a Part B and a Part D surcharge.
Two details catch people out. First, IRMAA is charged per person, so a married couple who both cross a threshold each pay the surcharge, doubling the household cost. Second, the Part D surcharge applies even if you hold a standalone drug plan or none at all, and it is billed separately from your plan premium. At the top tier a single beneficiary pays $689.90 a month for Part B plus a $91.00 Part D add-on, on top of the $202.90 base.
If your income has since dropped because of retirement, divorce, the death of a spouse, or another qualifying life-changing event, file Form SSA-44 rather than waiting for the annual recalculation. This calculator sizes the surcharge from your MAGI, but the appeal is where most overpayments are actually recovered.
Medicare IRMAA: frequently asked questions
What is IRMAA?
IRMAA (income-related monthly adjustment amount) is an extra charge added to your Medicare Part B and Part D premiums if your income is above a set threshold. It affects roughly 8% of people with Medicare. The 2026 Part B base premium is $202.90/month; higher earners pay more.
What income does 2026 IRMAA use?
IRMAA is based on your modified adjusted gross income (MAGI) from two years earlier: your 2024 MAGI determines your 2026 IRMAA. MAGI is your adjusted gross income plus tax-exempt interest.
How much is the IRMAA surcharge?
It depends on your MAGI tier. For example, a single filer with $150,000 MAGI is in tier 3: a Part B premium of $405.80 (a $202.90 surcharge over the base) plus a $37.50 Part D surcharge, $240.40 extra per month. See the full table below.
Can I appeal my IRMAA?
Yes. If your income has dropped because of a life-changing event (retirement, marriage, divorce, death of a spouse, loss of income), you can ask Social Security to use more recent income by filing Form SSA-44. IRMAA is otherwise recalculated each year from your latest tax return.
Official sources
- 2026 Part B premium and IRMAA brackets: CMS 2026 Medicare Parts A & B fact sheet, as at 15 July 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 15 July 2026. See our methodology. General information, not financial or medical advice.