Yes, IRMAA is recalculated every year. Each fall, the Social Security Administration reviews your tax return from two years prior and uses that income to determine whether you’ll pay a surcharge on your Medicare Part B and Part D premiums for the upcoming year. If your income changes from one year to the next, your IRMAA can go up, go down, or disappear entirely.
How the Two-Year Lookback Works
The SSA always bases your IRMAA on your modified adjusted gross income (MAGI) from two years before the current coverage year. For 2026 premiums, the SSA uses your 2024 tax return. For 2025 premiums, it used your 2023 return. If your return from two years ago isn’t available yet (because you filed an extension, for example), the SSA will use the return from three years prior instead.
Your MAGI for IRMAA purposes is straightforward: it’s your adjusted gross income (line 11 on your 1040) plus any tax-exempt interest income (line 2a). That second piece catches people off guard. Municipal bond interest, even though it’s not taxed, gets added back in and can push you into a higher IRMAA bracket.
The 2026 IRMAA Brackets
The income thresholds shift slightly each year to account for inflation. For 2026, the brackets based on 2024 income look like this:
If you file an individual tax return, you pay only the standard Part B premium of $202.90 per month as long as your MAGI is $109,000 or less. For joint filers, that threshold is $218,000 or less. Above those levels, surcharges kick in across five tiers:
- Tier 1: Individual income above $109,000 up to $137,000 (joint: above $218,000 up to $274,000). Part B premium rises to $284.10. Part D adds $14.50 to your plan premium.
- Tier 2: Individual income above $137,000 up to $171,000 (joint: above $274,000 up to $342,000). Part B rises to $405.80. Part D adds $37.50.
- Tier 3: Individual income above $171,000 up to $205,000 (joint: above $342,000 up to $410,000). Part B rises to $527.50. Part D adds $60.40.
- Tier 4: Individual income above $205,000 up to $500,000 (joint: above $410,000 up to $750,000). Part B rises to $649.20. Part D adds $83.30.
- Tier 5: Individual income at $500,000 or above (joint: $750,000 or above). Part B hits $689.90. Part D adds $91.00.
At the highest tier, you’d pay roughly $487 more per month in Part B premiums alone compared to someone below the first threshold. That’s nearly $5,850 per year in extra Part B costs, plus the Part D surcharge on top.
Married Filing Separately Is Treated Differently
If you’re married, file separately, and lived with your spouse at any point during the year, the brackets are much less forgiving. You get the same $109,000 floor as individual filers, but there are no intermediate tiers. Your next bracket jumps straight to the equivalent of Tier 4 once your income exceeds $109,000, and you hit the maximum surcharge at $391,000. This filing status effectively eliminates the lower IRMAA tiers that joint or individual filers can use.
When You’ll Find Out Your Amount
The SSA sends an Initial IRMAA Determination notice when it decides you owe a surcharge. Unlike some Medicare mailings that arrive on a predictable schedule, this notice can come at any time. Most people receive it late in the year before the new premiums take effect, but timing varies. The notice will spell out the exact income figure the SSA used, which bracket you fall into, and what your new monthly premium will be.
Because the determination happens annually, you could pay IRMAA one year and not the next. A one-time spike in income, like selling a property, exercising stock options, or taking a large Roth conversion, might trigger a surcharge for a single year. Once the two-year lookback window moves past that high-income year, your premiums drop back to the standard amount automatically. You don’t need to file anything for that to happen.
Requesting a Reduction After a Life Change
The two-year lookback can feel unfair if your financial situation has changed dramatically since the tax year being used. The SSA recognizes this and allows you to request a new determination based on more recent income if you’ve experienced a qualifying life-changing event. These include marriage, divorce, the death of a spouse, loss of income-producing property, loss or reduction of certain pension income, and an employer settlement payment.
Retirement itself often qualifies because it typically means a significant drop in earned income. If you retired in 2024 but your 2022 return (used for 2024 IRMAA) still reflected your full working salary, you can ask the SSA to use your current, lower income instead. You’ll need to complete Form SSA-44 and provide documentation of the event and your reduced income.
This is a request, not an automatic adjustment. You contact the SSA directly, explain the qualifying event, and provide evidence. If approved, your premiums are recalculated and the change can apply retroactively to the beginning of the year in some cases.
Strategies That Affect Your IRMAA Year to Year
Because IRMAA resets annually based on a single year’s income, the timing of income events matters more than most people realize. Converting a traditional IRA to a Roth IRA, for instance, adds the converted amount to your AGI for that year. A $100,000 conversion could push a joint filer from below the $218,000 threshold into the first or second IRMAA tier, adding thousands in Medicare surcharges two years later.
Spreading large income events across multiple tax years can keep you in a lower bracket or avoid IRMAA altogether. If you’re planning Roth conversions, capital gains harvesting, or the sale of a business, modeling the IRMAA impact for the year two years out is worth the effort. Even landing $1 above a bracket threshold triggers the full surcharge for that tier, so precision matters near the cutoffs.
Tax-exempt interest from municipal bonds is another area that catches retirees by surprise. While this income doesn’t appear on your taxable income, it’s explicitly added back in for the MAGI calculation used by IRMAA. A large municipal bond portfolio can contribute enough tax-exempt interest to push you into a higher bracket without any change to your tax bill.