Explainer
How does a Roth conversion affect Medicare IRMAA?
By Secure Retirement PlannerUpdated
If you do a Roth conversion in 2026, it can raise your Medicare premiums in 2028. For 2026 premiums, the surcharge starts when income is above $218,000 for married couples or $109,000 if you are single.
Medicare uses your modified adjusted gross income (MAGI) from two years earlier to set your Part B and Part D premiums. Your conversion adds to your MAGI.
IRMAA, the income-related monthly adjustment amount, is the surcharge added to your premium. It works in tiers. If you go $1 over a tier line, you pay that tier's full surcharge for the year. So the size of your conversion matters a lot once you're 63 or older.
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The short version
- Medicare looks back two years: 2026 income sets 2028 premiums.
- Each tier is a cliff. $1 over the line costs the full surcharge for that year.
- On a joint return, both spouses on Medicare pay the surcharge.
- A Roth conversion is not a life-changing event, so you can't get the surcharge lowered for it.
- Later, Roth withdrawals don't count in MAGI, which can help keep future premiums lower.
Which year's income does Medicare use for IRMAA?
Social Security sets your premium using your tax return from two years before. So your 2026 conversion shows up in your 2028 Medicare premiums.
That's why your conversions start to matter at 63. Your income at 63 sets your premiums at 65, the year most people start Medicare. If you convert before 63, it usually won't affect your Medicare premiums. The exception is if you are on Medicare early because of a disability.
| Conversion done in | Tax return | Affects Medicare premiums in |
|---|---|---|
| 2024 | 2024 return | 2026 |
| 2025 | 2025 return | 2027 |
| 2026 | 2026 return | 2028 |
| 2027 | 2027 return | 2029 |
What are the 2026 IRMAA brackets?
These are the 2026 tiers, based on 2024 income. The Part D amount is added to whatever your drug plan charges you. It applies if you have a Part D plan or a Medicare Advantage plan with drug coverage.
The lower tier lines usually rise each year with inflation. The 2028 lines that will apply to your 2026 income won't be known until late 2027. For a full breakdown, see 2026 IRMAA brackets and checker.
| Joint MAGI | Single MAGI | Part B per month | Part D add-on per month | Extra per person per year |
|---|---|---|---|---|
| $218,000 or less | $109,000 or less | $202.90 | $0 | $0 |
| Above $218,000 to $274,000 | Above $109,000 to $137,000 | $284.10 | $14.50 | $1,148.40 |
| Above $274,000 to $342,000 | Above $137,000 to $171,000 | $405.80 | $37.50 | $2,884.80 |
| Above $342,000 to $410,000 | Above $171,000 to $205,000 | $527.50 | $60.40 | $4,620.00 |
| Above $410,000, under $750,000 | Above $205,000, under $500,000 | $649.20 | $83.30 | $6,355.20 |
| $750,000 or more | $500,000 or more | $689.90 | $91.00 | $6,936.00 |
Why is IRMAA called a cliff?
Your income tax brackets only tax the dollars above a line at the higher rate. IRMAA doesn't work that way. If your MAGI is $1 over a tier line, you pay that tier's full surcharge for the whole year.
If you and your spouse are both on Medicare, going $1 over $218,000 adds about $2,297 for the year. Going $1 over $274,000 adds about $5,770 compared with your base premium.
What counts in MAGI
Your MAGI for IRMAA is your adjusted gross income plus tax-exempt interest. Your conversion, IRA withdrawals, the taxable part of your Social Security, capital gains and fund distributions all count.
Is it worth paying IRMAA to convert more?
Sometimes. IRMAA is a one-year cost for each high-income year. If you convert more now, you can lower your RMDs, and so your MAGI, for many years later.
Think of it as a fee on the slice of your conversion inside the tier. Say you and your spouse convert from $218,000 up to $274,000 of MAGI. You pay about $2,297 of IRMAA on a $56,000 slice. That's about 4.1% on top of your income tax on that slice.
Whether that pays off for you depends on your future RMDs and tax rates. It also depends on how long you expect to be on Medicare and on your heirs' tax rates. The Lowering tax on your RMDs guide covers the trade-off.
Can I appeal IRMAA after a Roth conversion?
Not because of your conversion. Social Security lowers IRMAA only for life-changing events, filed on Form SSA-44. Its rules list conversion of an IRA as an event that does not qualify.
Qualifying events include work stoppage or work reduction (such as retiring), marriage, divorce, death of a spouse, and loss of a pension. If you retired in a year that also had a conversion, you can still file for the work stoppage. Social Security then uses your new, lower income estimate. Any conversion you did that year still counts.
How do I size a conversion to stay under an IRMAA tier?
Add up everything that goes into your MAGI before you convert. Then convert only up to the tier line minus a cushion. You can do your final conversion in December, once you know your income for the year.
- Count your December mutual fund capital gain distributions. They can add thousands you didn't plan on.
- Include your tax-exempt interest. It counts for IRMAA even though it isn't taxed.
- Leave yourself a cushion of a few thousand dollars below the line.
- Use the current tier lines as a guide. The real lines for your premium year are set later and are usually a little higher.
Example: a couple at 66 sizing a 2026 conversion
Jim and Ellen are both 66 and file jointly. Before any conversion, their 2026 MAGI is $150,000 from pensions and investment income. They haven't claimed Social Security yet. Their 2026 conversion will set their 2028 Medicare premiums.
A $68,000 conversion brings MAGI to exactly $218,000, the top of the base tier. Converting $70,000 adds only $2,000 more. But it costs about $493 more in income tax and about $2,297 in IRMAA, so about $2,790 in all.
Their income tax on each extra dollar here is 24.64%, not 22%. Every dollar above $150,000 also cuts their $12,000 senior deduction by 12 cents (6 cents for each spouse).
If you are close to a tier line, a slightly smaller conversion can keep you out of a full year of higher Medicare premiums.
| Conversion | 2026 MAGI | Added 2026 federal tax | 2028 IRMAA for both (2026 rates) | Total added cost |
|---|---|---|---|---|
| $68,000 | $218,000 | about $16,755 | $0 | about $16,755 |
| $70,000 | $220,000 | about $17,248 | about $2,297 | about $19,545 |
| $124,000 | $274,000 | about $30,462 | about $2,297 | about $32,759 |
| $125,000 | $275,000 | about $30,702 | about $5,770 | about $36,472 |
Hypothetical example using 2026 federal brackets, deductions and IRMAA tiers (IRS Rev. Proc. 2025-32, Schedule 1-A, CMS). The 2028 tiers will be set later and will likely be higher. It assumes both spouses have Part B and Part D in 2028 and ignores state tax. Your numbers will differ.
Common questions
Does a Roth conversion count as income for Medicare premiums?
Yes. The converted amount is part of your adjusted gross income, which is the main piece of the MAGI Medicare uses. It affects premiums two years later.
If I convert in 2026, when will I see higher premiums?
In 2028. Social Security uses your 2026 tax return to set 2028 Part B and Part D premiums, and sends a notice before the year starts.
Do Roth IRA withdrawals count toward IRMAA?
Qualified Roth withdrawals are not taxable income, so they don't raise your MAGI. That's one reason some people convert before Medicare starts.
Does IRMAA last forever?
No. It's set one year at a time. If your income drops below the tier line in a later year, your premium two years after that goes back down.
Will I pay IRMAA if I convert at 62?
No. Income at 62 sets premiums at 64, before most people are on Medicare. Conversions start to count at 63.
Do both spouses pay IRMAA on a joint return?
Yes, if both are on Medicare. Each spouse pays the surcharge, which doubles the cost for the couple.
Are the 2027 IRMAA brackets out yet?
As of November 9, 2026, CMS had not published the official 2027 figures. Check CMS.gov before you rely on any 2027 number.
Sources
Facts on this page were last checked on November 9, 2026.
- CMS: 2026 Medicare Parts A & B premiums and deductibles · 2026 IRMAA tiers, Part B total premiums and Part D income-related amounts. Read Nov 9, 2026.
- SSA POMS HI 01101.010, Modified adjusted gross income · MAGI is AGI plus tax-exempt interest; tax year two years before the premium year. Read Nov 9, 2026.
- SSA POMS HI 01120.005, Life-changing events · Qualifying events; conversion of an IRA listed as non-qualifying. Read Nov 9, 2026.
- SSA: Request to lower an IRMAA (Form SSA-44) · How to request a new determination after a life-changing event. Read Nov 9, 2026.
- IRS Schedule 1-A (Form 1040), Additional Deductions · Senior deduction phase-out, 6% per qualifying spouse. Read Nov 9, 2026.
- IRS Rev. Proc. 2025-32 (2026 inflation adjustments) · 2026 brackets and standard deduction used in the example. Read Nov 9, 2026.
Who wrote this
This guide was written and fact-checked by the Secure Retirement Planner editorial team using IRS, CMS and Social Security sources listed above. We update guides when the law or yearly limits change. How we research.