Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Extra monthly cost from IRMAA
$87.70
Total Part B premium with IRMAA
$259.00
Total Part D premium with IRMAA
$58.70
Extra annual cost from IRMAA
$1,052
IRMAA bracket (0 = none)
1
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How to use this
- 1Enter magi from 2 years ago ($).
- 2Enter filing status.
- 3Enter standard part b premium ($).
- 4Enter your part d plan premium ($).
- 5Read your extra monthly cost from irmaa on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge added to Medicare Part B and Part D premiums for higher earners, based on your modified adjusted gross income (MAGI) from tax returns filed two years prior. So your 2025 Medicare premiums are based on your 2023 tax return. There are five brackets above the base premium threshold, each adding a progressively larger surcharge to both Part B and Part D. The brackets are not gradual phase-ins — crossing a threshold by even $1 pushes your entire premium into the next tier, which is why this is sometimes called a bracket cliff. Married couples filing jointly have roughly double the single thresholds. This calculator takes your MAGI from two years ago and filing status, finds your bracket, and shows the added monthly and annual surcharge on top of the standard premium, so you can see the cost of crossing a threshold before deciding on Roth conversions or other income moves.
Worked example
Using the values the calculator loads with:
Inputs
- MAGI from 2 years ago: 120000 $
- Filing status: Single / head of household
- Standard Part B premium: 185 $
- Your Part D plan premium: 45 $
Results
- Extra monthly cost from IRMAA: $87.70
- Total Part B premium with IRMAA: $259.00
- Total Part D premium with IRMAA: $58.70
- Extra annual cost from IRMAA: $1,052
- IRMAA bracket (0 = none): 1
What each field means
Inputs
- MAGI from 2 years ago ($)
- The magi from 2 years ago used in the calculation, measured in $. Starts at 120000 $ so you have a working example on load.
- Filing status
- Pick the option that matches your situation — the maths changes per option. Choices: Single / head of household, Married filing jointly.
- Standard Part B premium ($)
- The standard part b premium used in the calculation, measured in $. Starts at 185 $ so you have a working example on load.
- Your Part D plan premium ($)
- The your part d plan premium used in the calculation, measured in $. Starts at 45 $ so you have a working example on load.
Results
- Extra monthly cost from IRMAA
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total Part B premium with IRMAA
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total Part D premium with IRMAA
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Extra annual cost from IRMAA
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- IRMAA bracket (0 = none)
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why is my Medicare premium based on income from two years ago?
The IRS shares your most recently filed and processed tax return with SSA, which typically means a two-year lag — your 2025 premium uses 2023 MAGI. If your income dropped significantly due to a life-changing event like retirement, divorce, or loss of income, you can file Form SSA-44 to request a redetermination using more current income.
What counts as MAGI for IRMAA?
Adjusted gross income plus tax-exempt interest. This includes Roth conversion income, which is why large one-time conversions can unexpectedly push retirees into a higher IRMAA bracket for that specific tax year, even though the conversion isn't recurring income.
Is the IRMAA surcharge really a cliff, not a gradual increase?
Yes. Unlike income tax brackets where only the amount above a threshold is taxed at the higher rate, IRMAA applies the full surcharge for your entire premium once your MAGI crosses the line. Being $1 over a threshold can cost you hundreds extra per year, which is why careful income planning near bracket edges matters.
Can I appeal an IRMAA determination?
Yes, through Form SSA-44 for life-changing events (retirement, marriage, divorce, work stoppage, loss of pension) or by requesting reconsideration if you believe SSA used incorrect tax data. A permanent income drop isn't automatically fixed — you must proactively file the appeal.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Medicare IRMAA Bracket Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/irmaa-bracket-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/irmaa-bracket-cost" target="_blank" rel="noopener">Medicare IRMAA Bracket Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Medicare IRMAA Bracket Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/irmaa-bracket-cost) (2026).