Chapter 12: The IRMAA Cliff
The worksheets from Chapter 12 of Fifty-Five. Type your own numbers, or try an example from the book to see how each one works.
The 2026 IRMAA table
Your MAGI from two years earlier picks your row. Type your MAGI into a calculator below and it finds the row for you. Or find it here and work the paper worksheet.
| Row | Individual return MAGI | Joint return MAGI | Part B premium, a month | Part D surcharge, a month |
|---|---|---|---|---|
| 1 | $109,000 or less | $218,000 or less | $202.90 | $0.00 |
| 2 | Over $109,000 up to $137,000 | Over $218,000 up to $274,000 | $284.10 | $14.50 |
| 3 | Over $137,000 up to $171,000 | Over $274,000 up to $342,000 | $405.80 | $37.50 |
| 4 | Over $171,000 up to $205,000 | Over $342,000 up to $410,000 | $527.50 | $60.40 |
| 5 | Over $205,000 and under $500,000 | Over $410,000 and under $750,000 | $649.20 | $83.30 |
| 6 | $500,000 or more | $750,000 or more | $689.90 | $91.00 |
Married filing separately, if you lived with your spouse at any time in the year
| Row | MAGI | Part B premium, a month | Part D surcharge, a month |
|---|---|---|---|
| 1 | $109,000 or less | $202.90 | $0.00 |
| 2 | Over $109,000 and under $391,000 | $649.20 | $83.30 |
| 3 | $391,000 or more | $689.90 | $91.00 |
MAGI here is your adjusted gross income plus any tax-exempt interest. The Part D surcharge is added to your plan's own premium. Each person on Medicare pays these amounts.
Where these figures come from: The 2026 Part B premium and Part D surcharge for every row of the IRMAA table, used when you type your MAGI (CMS, 2026 Medicare Parts A & B Premiums and Deductibles); The 2026 IRMAA income lines for individual, joint and married-filing-separately returns (SSA, Premiums: Rules for Higher-Income Beneficiaries). They are the 2026 amounts and they change every year.
What one more step costs
What it costs for a year to cross from the IRMAA row you are in to the next one up.
The formula: (Next row's Part B − Your row's Part B) + (Next row's Part D − Your row's Part D) = Extra per month, per person. Then × 12 = Extra per year, per person. Then × the number of people on Medicare = Household cost of the step.
The calculator needs JavaScript. The paper worksheet below does not: it is the same arithmetic, written out.
The paper worksheet
Part B difference: Next row's Part B $__________ − Your row's Part B $__________ = $__________
Part D difference: Next row's Part D $__________ − Your row's Part D $__________ = $__________
Extra per month: Part B difference $__________ + Part D difference $__________ = $__________
Extra per month $__________ × 12 × People on Medicare ______ = Cost of the step for the year $__________
Walk through it, step by step
- Find your row in the Chapter 11 table, using your expected MAGI and your filing status.
- Find the next row down. That is the step you are trying not to cross.
- Subtract your row's Part B premium from the next row's. Write the answer.
- Subtract your row's Part D surcharge from the next row's. Write the answer.
- Add the answers from Steps 3 and 4. That is the extra per month, per person.
- Multiply by 12. On paper, multiply by 10, multiply by 2, and add the two answers.
- Multiply by 1 or 2, for the number of people in your household on Medicare.
- Write the result on the last blank. Compare it with what you'd gain from the extra income.
Check your answer
- Every step costs the same no matter how far past the line you go. Being $1 over costs the same as being $27,000 over.
- If your answer changed with the amount over, you multiplied by the wrong thing.
Figures this worksheet uses, and where they come from: The 2026 standard Part B premium ($202.90) and the 2026 Part B and Part D IRMAA amounts you look up for each row (CMS, 2026 Medicare Parts A & B Premiums and Deductibles); The 2026 Part B premium and Part D surcharge for every row of the IRMAA table, used when you type your MAGI (CMS, 2026 Medicare Parts A & B Premiums and Deductibles); The 2026 IRMAA income lines for individual, joint and married-filing-separately returns (SSA, Premiums: Rules for Higher-Income Beneficiaries).
How much you can add and stay under
The most you can add this year, in a Roth conversion, a sale or a bonus, and still land under the next IRMAA line with a cushion to spare.
The formula: Next IRMAA line − Income you already expect − Your cushion = The most you can add
The calculator needs JavaScript. The paper worksheet below does not: it is the same arithmetic, written out.
The paper worksheet
Next line $__________ − Income already expected $__________ = Room to the line $__________
Room to the line $__________ − Your cushion $__________ = Most you can add $__________
Walk through it, step by step
- Fill in the MAGI worksheet in Chapter 3 for this year, without the conversion, sale or bonus you're deciding about. That total is your income already expected. Write it on the second blank.
- Find the next line above that income in the Chapter 11 table, in your column (individual or joint). Write it on the first blank.
- Subtract the second blank from the first. Write it on the third blank. That is your room right up to the line.
- Choose a cushion. Write it on the fourth blank.
- Subtract the cushion from your room. Write it on the last blank. That is the most to add this year.
- If the answer is zero or less, you are already inside your cushion. Add nothing more this year, or move income to next year if you can.
- Wait until December to do the last piece, once you can see the rest of the year's income.
Check your answer
- Add three numbers: income already expected + the most you can add + your cushion. You should get exactly the line.
- For Margaret: $70,000 + $36,000 + $3,000 = $109,000. It matches.
Figures this worksheet uses, and where they come from: The 2026 IRMAA income lines used in the examples: $109,000 on an individual return, $274,000 on a joint return (SSA, Premiums: Rules for Higher-Income Beneficiaries).