The IRMAA cliff: $1 over a bracket
By Elder PaperworkUpdated
Short answer
IRMAA is charged by brackets, not on a sliding scale.
Going $1 over a 2026 threshold means paying the whole amount for the next bracket.
At $109,001 of MAGI (single), that is $81.20 more for Part B and $14.50 for Part D each month.
Source: CMS, November 14, 2025. Read November 4, 2026.
Key facts
Why does $1 make a difference?
Each bracket has a fixed amount. Above the line, you pay that bracket’s full amount.
| Single | Joint | Part B total | Part D extra |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 | $0.00 |
| Up to $137,000 | Up to $274,000 | $284.10 | $14.50 |
| Up to $171,000 | Up to $342,000 | $405.80 | $37.50 |
| Up to $205,000 | Up to $410,000 | $527.50 | $60.40 |
| Under $500,000 | Under $750,000 | $649.20 | $83.30 |
| $500,000 or more | $750,000 or more | $689.90 | $91.00 |
What does it cost to be just over?
Single, $109,000 of MAGI: no IRMAA. At $109,001: $95.70 a month, or $1,148.40 a year.
For a married couple on a joint return, each spouse pays it.
How do I check my bracket?
Use your MAGI: AGI (Form 1040, line 11) plus tax-exempt interest (line 2a).
Enter it in the IRMAA 2026 calculator.
See your possible savings first. No commitment.
Check my savingsCan you help me stay under the line?
No. We don’t give tax planning advice. Ask a tax professional.
We help when a life-changing event lowered your income.
Questions
Is IRMAA a sliding scale?
No. It goes by brackets, so $1 over a threshold triggers the full bracket amount.
Where is the first cliff in 2026?
Above $109,000 of MAGI for single filers, $218,000 for joint.
Do you give tax planning advice?
No. Ask a tax professional for that.