Do Roth conversions affect Medicare premiums? Yes, they can, through one mechanism: a Roth conversion is taxed as ordinary income, that income raises your modified adjusted gross income (MAGI), and MAGI is exactly what Medicare uses to decide whether you owe the Income-Related Monthly Adjustment Amount (IRMAA), a surcharge on Part B and Part D. Because IRMAA runs on a two-year lookback, a conversion you make in 2026 can raise your premiums in 2028.
Yes. A Roth conversion is taxed as ordinary income and adds dollar for dollar to your MAGI, which can push you into IRMAA, a surcharge Medicare adds to both Part B and Part D. Because IRMAA uses a two-year lookback, a 2026 conversion sets your 2028 premiums. In 2026 the standard Part B premium is $202.90 per month, and IRMAA begins above $109,000 (single) or $218,000 (joint) MAGI. (Source: CMS 2026 Fact Sheet; SSA POMS HI 01101.020)
What is IRMAA, and how does a Roth conversion trigger it?
IRMAA (the Income-Related Monthly Adjustment Amount) is an income surcharge Medicare adds on top of your Part B premium and, separately, on top of your Part D drug premium once your MAGI clears a threshold. A Roth conversion triggers it because the converted amount is taxable ordinary income that adds directly to MAGI, which for IRMAA equals adjusted gross income plus tax-exempt interest.
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IRMAA has adjusted Part B premiums by income since 2007 and reaches roughly 8% of Part B beneficiaries (Source: SSA Benefits Planner, treated as approximate). For 2026, the standard Part B premium is $202.90 per month, up from $185.00 in 2025, and the annual Part B deductible is $283 (Source: CMS “2026 Medicare Parts A and B Premiums and Deductibles,” Nov 14, 2025). A beneficiary whose MAGI stays below the first threshold pays that standard $202.90 with no Part B surcharge and no Part D surcharge. Cross the threshold, and IRMAA is added on both parts.
For IRMAA, MAGI equals your AGI (Form 1040, line 11) plus any tax-exempt interest (line 2a), so tax-free municipal bond interest is added back and does not shelter you from the threshold math (Source: SSA POMS HI 01101.010). A Roth conversion moves money from a tax-deferred traditional IRA or 401(k) into a Roth account, where future growth and qualifying withdrawals are tax-free. You pay ordinary income tax now on the amount converted, there is no dollar limit and no income cap, and that full amount lands in AGI. Unlike a qualified Roth withdrawal, which never counts as income, the conversion event itself is the taxable moment, which is why the link to your Medicare premium is so direct.
One detail surprises couples: IRMAA is assessed per beneficiary. If both spouses are enrolled in Medicare and the household MAGI lands in a surcharge tier, each spouse pays the surcharge separately (Source: SSA POMS HI 01101.020). A single high-income year can therefore mean two surcharges in one household.
The two-year lookback: a 2026 conversion sets your 2028 premiums
Medicare does not use current income to set IRMAA. It uses your most recent federal return on file, generally the return from two years prior. So 2026 IRMAA is based on 2024 income, and a conversion you complete in 2026 sets your Part B and Part D surcharges for 2028 (Source: SSA POMS HI 01101.030). If two-year-prior data is unavailable, SSA may use three-year-prior data.
The lookback is a commonly misunderstood part of this topic. Retirees often expect a surcharge letter the same year they convert, then feel blindsided two years later. The practical planning point is that a conversion done in 2026 does not touch your 2026 or 2027 premiums at all; it lands in 2028. That two-year gap is also why timing conversions before you enroll in Medicare matters, which we cover below.
2026 IRMAA brackets: Part B and Part D by filing status
The 2026 IRMAA tables use MAGI from two years prior (2024 income). The table below shows the sliding scale for single and married-filing-jointly filers, with the total monthly Part B premium (standard $202.90 plus surcharge) and the Part D surcharge added to your drug plan premium (Source: SSA POMS HI 01101.020, updated Dec 2, 2025). Thresholds are indexed to inflation each year, except the top single and joint tiers, which are fixed by statute.
| Single / HOH MAGI (2024 income) | MFJ MAGI (2024 income) | Total Part B / month | Part D surcharge / month |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 (no IRMAA) | $0.00 |
| Over $109,000 to $137,000 | Over $218,000 to $274,000 | $284.10 | plus $14.50 |
| Over $137,000 to $171,000 | Over $274,000 to $342,000 | $405.80 | plus $37.50 |
| Over $171,000 to $205,000 | Over $342,000 to $410,000 | $527.50 | plus $60.40 |
| Over $205,000 to under $500,000 | Over $410,000 to under $750,000 | $649.20 | plus $83.30 |
| $500,000 or more | $750,000 or more | $689.90 | plus $91.00 |
Married filing separately follows a compressed scale: MAGI above $109,000 to under $391,000 pays $649.20 for Part B plus an $83.30 Part D surcharge, and $391,000 or more pays $689.90 plus $91.00 (Source: SSA POMS HI 01101.020). A separated filer who lived apart from a spouse for the entire year may use the single table instead.
The cliff effect: one dollar over a threshold costs the whole tier
IRMAA is a cliff, not a gradual phase-in. Crossing a threshold by a single dollar moves you into the next tier’s full surcharge for all 12 months of the year (Source: SSA POMS HI 01101.020, which uses discrete brackets with no interpolation). A conversion that lands your MAGI $1 over a line can cost the same as one that lands you thousands over it, which is why conversion sizing is precise work.
Consider a single retiree with MAGI at $137,000 versus $137,001. The first pays $284.10 per month for Part B; the second pays $405.80, about $121.70 more each month, roughly $1,460 more over the year, plus a larger Part D surcharge, all triggered by one extra dollar of income. This is the opposite of the marginal income tax brackets most people picture, where only the dollars above a line are taxed at the higher rate. With IRMAA, the entire year’s surcharge steps up at once.
Worked example: what a $100,000 Roth conversion can cost
A $100,000 Roth conversion that pushes a single filer from $90,000 to $190,000 of MAGI moves them from paying no IRMAA into the fourth tier, raising Part B to $527.50 per month and adding a $60.40 Part D surcharge. The combined IRMAA attributable to that conversion is roughly $4,620 for the single year the surcharge applies, two years after the conversion. The figures below are hypothetical illustrations, not real clients or projections.
Hypothetical single filer, $100,000 conversion
A single retiree with a baseline MAGI of $90,000 pays no IRMAA. Converting $100,000 lifts MAGI to $190,000, into the over-$171,000-to-$205,000 tier, so Part B rises to $527.50 monthly and Part D adds $60.40. The combined surcharge attributable to the conversion is roughly $4,620 for the single year it applies, two years later. This is a hypothetical illustration.
Assume a single retiree with a baseline MAGI of $90,000, below the $109,000 first threshold, so with no conversion they pay no IRMAA. They convert $100,000, and MAGI rises to $190,000, landing in the “over $171,000 to $205,000” tier.
- Part B rises from $202.90 to $527.50 per month, a surcharge of $324.60 per month, about $3,895 for the year.
- Part D adds a $60.40 monthly surcharge, about $725 for the year.
- Combined IRMAA attributable to the conversion: roughly $4,620 for that one year.
Hypothetical married couple, $100,000 conversion
A couple with a baseline joint MAGI of $200,000 pays no IRMAA. Converting $100,000 lifts MAGI to $300,000, into the MFJ over-$274,000-to-$342,000 tier. Because IRMAA is assessed per beneficiary, each enrolled spouse pays a surcharge: Part B of $405.80 and Part D of $37.50. Together the two surcharges total roughly $5,770 for that one year. This is a hypothetical illustration.
Assume a couple, both enrolled in Medicare, with a baseline joint MAGI of $200,000 and no IRMAA. They convert $100,000, lifting MAGI to $300,000, which lands in the MFJ “over $274,000 to $342,000” tier. Because IRMAA is per beneficiary, each spouse pays a surcharge.
- Each spouse’s Part B rises to $405.80 per month, a surcharge of $202.90 each, about $2,435 per person for the year.
- Each spouse’s Part D adds $37.50 per month, about $450 per person.
- Two beneficiaries combined: roughly $5,770 in IRMAA for that single year.
These surcharges apply for one year, then reset once your MAGI returns to its normal level. The IRMAA cost of a conversion is a one-year event, not a permanent increase.
How much can you convert before triggering IRMAA?
Your conversion ceiling is the amount you can convert before your MAGI crosses the next IRMAA threshold. The method: project your MAGI for the conversion year without the conversion, then subtract that from the next threshold for your filing status. The difference is your headroom under that cliff. This is a repeatable calculation you can run every tax year with your own numbers.
Here is the process as a worksheet:
- Estimate your MAGI for the year without any conversion: pensions, interest, dividends, the taxable share of Social Security, RMDs if applicable, then add back tax-exempt interest.
- Identify the IRMAA threshold you want to stay under for your filing status, from the 2026 table above.
- Subtract your projected MAGI from that threshold. The result is your headroom, the largest conversion that keeps you under that cliff.
- Remember the two-year lookback: the ceiling you calculate for a 2026 conversion protects your 2028 premiums.
Single example. Projected MAGI is $95,000. To avoid any IRMAA, the ceiling is the first threshold, $109,000, minus $95,000, which is $14,000. To instead fill the first surcharge tier and stop before the second cliff at $137,000, the ceiling would be $42,000.
Married example. A couple’s projected joint MAGI is $180,000. To avoid any IRMAA, the ceiling is $218,000 minus $180,000, which is $38,000 of conversion room before the first joint cliff.
Filling a tier deliberately, rather than avoiding IRMAA entirely, is a common approach when the goal is to reduce future RMDs. Deciding how much to convert to a Roth in any year is where the IRMAA ceiling and your marginal income tax bracket both matter.
The pre-Medicare window: why the year you turn 63 is the cutoff
Conversions completed before your income enters Medicare’s lookback have no IRMAA effect on you, because there is no premium to surcharge yet. Given the two-year lookback, income in the year you turn 63 is the first that sets IRMAA, for the year you turn 65. Conversions through the year you turn 62 do not affect any Medicare premium, so many retirees treat the years before 63 as a low-friction time to convert.
This window is often a clean opportunity in a conversion plan. Between age 59.5, when the 10% early-distribution penalty no longer applies, and the year you turn 62, a conversion adds to your income tax bill but carries no IRMAA consequence, because your first Medicare premium year has not yet entered the lookback. Retirees who have stopped working but not yet claimed Social Security often find these are their lowest-income years, which can make the tax cost of converting lower as well.
How to reduce or avoid IRMAA from a Roth conversion
Because a voluntary conversion is not an appealable event, the planning happens before you convert. Common levers to reduce or avoid IRMAA include spreading conversions across several years to stay under a threshold, converting in the lower-income years before you turn 63, and managing other pieces of MAGI so a conversion has more headroom under the next cliff. Sizing each conversion to that headroom is the main control.
Approaches many retirees consider, each of which may or may not fit a given situation:
- Spread conversions over multiple years. A series of smaller conversions can fill a tax bracket or an IRMAA tier each year without spiking MAGI into a high surcharge in any single year.
- Convert before age 63. Completing conversions in the years before the lookback reaches age 63 keeps them out of the IRMAA calculation entirely.
- Use qualified charitable distributions (QCDs). A QCD sends IRA dollars directly to charity, excludes that amount from income, and can lower the RMD-driven MAGI that otherwise stacks on top of conversion income. QCDs are available from an IRA (not directly from a 401(k)) starting at age 70.5.
- Fund an HSA while eligible. HSA contributions reduce AGI, and by extension MAGI, in the contribution year, though eligibility ends once you enroll in Medicare.
- Harvest tax losses. Realized capital losses can offset capital gains and trim AGI in the same year as a conversion.
- Watch the December 31 deadline. A conversion counts in the year it is completed, and the Roth conversion deadline is December 31, so late-year projections of MAGI drive the sizing decision.
A conversion is not itself net investment income, but by raising MAGI it can expose other investment income to the 3.8% net investment income tax above $200,000 (single) or $250,000 (joint), a separate cost worth checking alongside IRMAA.
Is one year of IRMAA worth it? The RMD and tax-torpedo trade-off
The honest way to weigh it is as a one-time toll against a lifetime cost. IRMAA from a conversion is finite: it applies for the single year your MAGI is raised, then resets. The income tax drag from required minimum distributions is not finite; it can recur every year for the rest of your life and your spouse’s. Comparing a one-year surcharge to a multi-decade RMD stream is the core trade-off.
Converting before RMDs begin reduces the traditional IRA balance that will later be forced out as taxable income. Under current law, RMDs begin at age 73, or age 75 for those born in 1960 or later, with the first age-75 RMD year arriving in 2035 (Source: IRS, SECURE 2.0 Act RMD rules). Those distributions raise MAGI every year, which can push IRMAA higher year after year, and they cannot be avoided once they start, aside from qualified charitable distributions.
For retirees already claiming Social Security, a conversion can do double damage in the conversion year. The added income can raise the share of Social Security benefits that is taxable, up to 85%, through the provisional-income formula, and can push MAGI into an IRMAA tier at the same time. This combined effect is often called the tax torpedo, and it is a reason some retirees convert before claiming benefits.
So the framing is not “does a conversion raise my Medicare premium” in isolation. It is whether accepting a one-year surcharge now may be preferable to a potentially larger and repeating IRMAA and income tax exposure later. The answer depends on your balances, tax bracket, and time horizon, and the math can cut both ways. A Roth conversion break-even analysis and a review of your projected required minimum distributions are the two pieces that make this concrete for a given household. This is educational information, not a recommendation to convert.
Can you appeal higher Medicare premiums from a conversion?
Generally, no. IRMAA can be reduced only for a qualifying life-changing event filed on Form SSA-44, and a voluntary Roth conversion is not on that list (Source: SSA POMS HI 01120.005; Form SSA-44). The qualifying events are circumstances outside your control, such as work stoppage or loss of a pension. Because a conversion is a chosen action, the resulting surcharge is not appealable, which makes sizing the conversion correctly the main control you have.
The eight qualifying life-changing events on Form SSA-44 are: marriage; divorce or annulment; death of a spouse; work stoppage; work reduction; loss of income-producing property beyond your control; loss or reduction of certain pension income; and an employer settlement payment (Source: SSA “Request to lower IRMAA”; SSA POMS HI 01120.005). None covers voluntary conversion income. Setting this expectation honestly matters: if you convert and cross a threshold, you cannot later ask Social Security to undo the surcharge on the grounds that it was a one-time event. The planning happens before the conversion, not after the premium letter arrives.
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Frequently asked questions
These answers summarize how a Roth conversion interacts with Medicare IRMAA surcharges, drawn from the SSA and CMS sources cited above. They cover whether a conversion counts as income, how much you can convert, how long a surcharge lasts, the age cutoff, the two-year timing, how to avoid an increase, and whether the surcharge can be appealed. This is educational information, not personalized advice.
Do Roth conversions count as income for Medicare premiums?
Yes. A Roth conversion is taxed as ordinary income and adds to your adjusted gross income, and Medicare measures MAGI, which equals AGI plus tax-exempt interest (Source: SSA POMS HI 01101.010). The full converted amount counts, with no dollar or income cap. That is the direct link between a conversion and a possible Part B and Part D surcharge two years later.
How much can I convert to a Roth without triggering IRMAA?
Subtract your projected MAGI for the year from the next IRMAA threshold for your filing status; the difference is the largest conversion that stays under that cliff. For 2026 the first thresholds are $109,000 (single) and $218,000 (joint) (Source: SSA POMS HI 01101.020). A single filer with $95,000 of projected MAGI has about $14,000 of room before the first surcharge tier.
How many years does a Roth conversion affect my Medicare premiums?
One year. IRMAA is assessed on the MAGI from a single tax year, so a one-time conversion raises premiums only for the one year that raised income governs, then resets once your MAGI returns to normal (Source: SSA POMS HI 01101.020). Because of the two-year lookback, that surcharge year falls two years after the year you convert.
At what age do Roth conversions stop affecting Medicare?
A conversion affects Medicare only once its income year enters the two-year lookback. Conversions completed through the year you turn 62 do not affect any premium. The year you turn 63 is the first whose income sets a Medicare premium, the one you pay at 65 (Source: SSA POMS HI 01101.030). Converting in the years before 63 avoids the IRMAA link entirely.
Does a Roth conversion affect IRMAA the same year or two years later?
Two years later. Medicare sets IRMAA from your most recent return on file, generally the return from two years prior, so a 2026 conversion affects your 2028 Part B and Part D premiums, not your 2026 premiums (Source: SSA POMS HI 01101.030). This gap surprises many retirees, who expect a surcharge in the same year they convert.
How do I avoid a Medicare premium increase after a Roth conversion?
Common approaches include spreading conversions across several years to stay under a threshold, converting in the lower-income years before you turn 63, and managing other MAGI levers such as qualified charitable distributions from an IRA (age 70.5 or older) and HSA contributions while eligible. Sizing each conversion to your headroom under the next cliff is the main control (Source: SSA POMS HI 01101.020).
Can I appeal higher Medicare premiums caused by a Roth conversion?
Generally no. IRMAA can be reduced only through Form SSA-44 for a qualifying life-changing event, such as work stoppage, divorce, or loss of a pension, all outside your control (Source: SSA POMS HI 01120.005). A voluntary Roth conversion is not a qualifying event, so the resulting surcharge cannot be appealed. Sizing the conversion in advance is the main lever.
Sources
These figures come from primary government sources: CMS for the 2026 Part B premium and deductible, SSA Program Operations Manual System (POMS) sections for the IRMAA sliding-scale tables, MAGI definition, two-year lookback, and life-changing-event rules, and IRS guidance for SECURE 2.0 RMD ages. Each is listed below so you can verify every number against its original publication.
CMS, “2026 Medicare Parts A and B Premiums and Deductibles” Fact Sheet (Nov 14, 2025); SSA POMS HI 01101.020, “IRMAA Sliding Scale Tables” (updated Dec 2, 2025); SSA POMS HI 01101.010, “Modified Adjusted Gross Income (MAGI)”; SSA POMS HI 01101.030, “Two-Year Lookback / IRS Data”; SSA POMS HI 01120.005, “Life-Changing Events” and Form SSA-44; SSA Benefits Planner, “Medicare Premiums”; IRS, SECURE 2.0 Act RMD rules and 2026 retirement figures.
