Medicare can charge higher Part B and Part D premiums when your income is above certain limits, and those higher premiums are called IRMAA (Income-Related Monthly Adjustment Amount). The catch is timing. IRMAA is usually based on your tax return from two years earlier. So a bump in part-time income or a big IRA withdrawal this year can raise your Medicare costs two years from now.
This guide explains what triggers IRMAA, the 2026 thresholds, the income events that surprise semi-retirees most often, and the planning moves that help you avoid avoidable premium spikes.
Key Takeaways
- IRMAA for a given year is generally based on your MAGI from two years before.
- Going even $1 over a threshold can push you into a higher tier for the year.
- The best way to avoid surprises is to coordinate part-time income, IRA withdrawals, Roth conversions, and capital gains so you do not create avoidable premium spikes.
- After certain qualifying life-changing events, you may be able to appeal IRMAA using Form SSA-44.
What Is Medicare IRMAA and What Triggers It?
IRMAA is an income-based surcharge that can be added to Medicare Part B (medical insurance) and Medicare Part D (prescription drug coverage). It is not a permanent tax. Social Security reviews it each year based on your income, and your IRMAA tier can change from year to year.
What Income Does Medicare Look At?
For IRMAA, Social Security uses a version of income called Modified Adjusted Gross Income (MAGI). This is essentially your Adjusted Gross Income (AGI) plus any tax-exempt interest, which often includes interest from municipal bonds.
That definition matters for one important reason. You can cross an IRMAA threshold even if part of the income involved is “tax-free” interest. Tax-exempt for income tax purposes does not mean tax-exempt for IRMAA purposes.
What Are the 2026 IRMAA Thresholds?
In 2026, most people pay the standard Part B premium. IRMAA starts once your 2024 MAGI goes over the first threshold. The first tier begins above $109,000 for single filers and above $218,000 for married couples filing jointly.
Part D has IRMAA tiers too, and those charges are added on top of your Part D plan premium. The main point to remember is that 2026 premiums are generally based on your 2024 tax return, not your current income.
This is the two-year lookback that creates so many surprises. By the time you see the higher premium notice, the income event that caused it may already be two years in the past.
Which Income Events Often Surprise Semi-Retirees?
Part-time work is only one way people accidentally trigger IRMAA. Many “one-time” moves can raise MAGI quickly, especially in years where retirees expected lower income.
Part-Time or Consulting Income
A short contract or a strong consulting year can be enough to bump you into the next tier, especially if you were already close to the line. This catches many semi-retirees who took on a project without modeling its IRMAA impact two years ahead.
Extra IRA Withdrawals
Large withdrawals for a remodel, a car purchase, debt payoff, or a big travel year can raise MAGI fast. The withdrawal feels like a one-time event, but its IRMAA effect shows up on Medicare bills two years later.
Roth Conversions
Roth conversions count as taxable income. Even if the strategy makes sense long-term, the conversion year can push you into an IRMAA tier. That does not mean conversions are a bad idea. It just means the amount and timing should be planned with IRMAA in mind.
Capital Gains
Selling appreciated investments or real estate can create a sudden income spike. Concentrated stock sales, rental property sales, or rebalancing a long-held portfolio can all trigger IRMAA without much warning.
Tax-Exempt Interest
Municipal bond interest is often tax-exempt for income tax purposes, but it is still included in MAGI for IRMAA. Retirees who shift heavily into munis sometimes assume that income is invisible for Medicare. It is not.
Which Planning Moves Reduce IRMAA Surprises?
Most IRMAA planning comes down to one idea, which is to smooth your income instead of stacking it all into one year. The five strategies below work well together.
1. Spread Income Across Tax Years When Possible
If you need a large amount of cash, it may help to split it over two years, depending on your baseline income and deductions. For example, taking part of a withdrawal late in one year and part early in the next can keep both years under a higher tier.
This is not always the best move, but it is often worth modeling before a large withdrawal.
2. Coordinate Work Income With Withdrawals
If a year is already high because you are working part-time, you may be able to reduce IRA withdrawals or delay discretionary investment sales so total MAGI stays steadier. Treating work income and withdrawals as one combined picture helps prevent stacking events that push you across a threshold.
3. Size Roth Conversions With IRMAA in Mind
Roth conversions can be powerful, but the amount matters. If you are near an IRMAA threshold, the conversion should usually be sized to avoid stepping into a higher tier without a clear reason. Sometimes a slightly smaller conversion saves more in Medicare premiums than the larger conversion saves in future taxes.
4. Think Two Years Ahead
A simple habit helps a lot. Treat IRMAA as a two-years-forward planning problem.
If you make an income decision in 2026, ask what it might do to your Medicare premiums in 2028. Just asking the question protects you from many of the most common surprises.
5. Know You May Be Able to Appeal After a Life Change
If IRMAA is based on older income that no longer reflects your current situation, Social Security allows an appeal process for certain qualifying life-changing events. These can include retirement, the loss of a spouse, divorce, or a major reduction in work hours.
The appeal is filed using Form SSA-44. It will not help with every IRMAA situation, but it is worth knowing about if your income has dropped significantly since the lookback year.
FAQs
Medicare looks at your MAGI, which is generally your AGI plus tax-exempt interest. If your MAGI for the lookback year crosses a threshold, IRMAA applies for the current Medicare year.
Usually a two-year lookback. For example, 2026 premiums are generally based on 2024 income.
Yes. Roth conversions increase taxable income and can push MAGI into a higher IRMAA tier in the year of the conversion.
Start with your most recent tax return, estimate your MAGI, and compare it to the published IRMAA brackets for the Medicare year you are planning for.
Yes. Realized capital gains flow through your AGI and into MAGI, which can push you into a higher IRMAA tier.
Possibly. Social Security accepts appeals through Form SSA-44 after certain life-changing events, including work stoppage or work reduction. The appeal is most useful when your current income is significantly lower than the lookback year.
No. Although municipal bond interest is generally tax-exempt for federal income tax purposes, it is still added back into MAGI for IRMAA calculations.
Avoid Surprise Medicare Premium Jumps
If you are earning part-time income, doing Roth conversions, or planning larger withdrawals, the most helpful next step is to build a simple two-year-forward income map so IRMAA does not sneak up on you. Once you can see income, withdrawals, and conversions on one page, the right size and timing usually become clear.
At Bauman Wealth Advisors, our CFP® professionals coordinate your income, withdrawals, and tax strategy so your Medicare costs stay as predictable as possible.
Ready to keep your premiums in check? Schedule a complimentary consultation with our team today and turn IRMAA from a surprise bill into a planned line item in your retirement budget.
