A Roth conversion IRMAA problem can arise because the taxable amount of a conversion is added to income, and Social Security uses that income to decide whether a Medicare beneficiary pays more than the standard 2026 Part B premium of $202.90 per month.1,2,4 For 2026, higher premiums begin above $109,000 of modified adjusted gross income (MAGI) for individual filers and above $218,000 for joint filers.1
This article explains what IRMAA is, how conversion income flows into MAGI, how the two-year lookback works, the 2026 Part B and Part D brackets, why a single dollar can matter, educational planning considerations, and when Form SSA-44 may or may not help.
Quick Answer A Roth conversion can raise Medicare premiums because the taxable conversion amount is included in adjusted gross income, and Social Security defines MAGI for IRMAA as adjusted gross income plus tax-exempt interest.2,4 Social Security generally uses the tax return from two years before the premium year, so a 2026 conversion would generally affect 2028 premiums.3 For 2026, IRMAA starts above $109,000 (individual) or $218,000 (joint) of MAGI.1 A voluntary Roth conversion is not among the life-changing events listed in the regulations, so Form SSA-44 does not apply to it.3,5 |
What Is IRMAA?
The income-related monthly adjustment amount (IRMAA) is an additional charge that higher-income Medicare beneficiaries pay on top of the standard Part B premium and their Part D plan premium.1,2 Social Security determines whether IRMAA applies using a sliding scale based on MAGI from the most recent federal tax return the IRS provides, and it sends a letter listing the premium amounts and the reason for the determination.2
Social Security defines MAGI for this purpose as “your total adjusted gross income and tax-exempt interest income.”2 The federal regulations add several smaller items, including foreign earned income and certain U.S. savings bond interest used for higher education.3
How a Roth Conversion IRMAA Increase Happens
According to the IRS, “a conversion to a Roth IRA results in taxation of any untaxed amounts in the traditional IRA,” and the conversion is reported on Form 8606.4 Because the taxable portion of the conversion becomes part of adjusted gross income, it also becomes part of the MAGI that Social Security uses for IRMAA.2,3,4
Two features can make this especially relevant for conversions:
No undo. Since January 1, 2018, a conversion from a traditional, SEP, or SIMPLE IRA to a Roth IRA cannot be recharacterized, so an IRMAA consequence cannot be reversed by unwinding the conversion.4
One-time spikes count fully. The determination uses the MAGI reported for the relevant tax year, so a single large conversion year is measured the same way as recurring income.3
The Two-Year Lookback
Under the regulations, Social Security generally uses MAGI reported by the IRS for the tax year two years before the premium year, and it may use the year three years before if the two-year-prior information is not available.3 For 2026 premiums, Social Security states that it generally uses the 2024 tax return filed in 2025.2
Applying that same rule, by our calculation a conversion completed in 2026 would generally be reflected in 2028 premiums, and those premiums would be measured against the 2028 brackets, which have not yet been published.3 By the same arithmetic, income in the year a person turns 63 can be used for premiums in the year that person turns 65, so income earned before Medicare enrollment can matter.3
2026 Part B and Part D IRMAA Brackets
| 2024 MAGI: Individual | 2024 MAGI: Joint | Total Monthly Part B Premium | Part D Monthly IRMAA |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.901 | $0.001 |
| $109,001–$137,000 | $218,001–$274,000 | $284.101 | $14.501 |
| $137,001–$171,000 | $274,001–$342,000 | $405.801 | $37.501 |
| $171,001–$205,000 | $342,001–$410,000 | $527.501 | $60.401 |
| $205,001–less than $500,000 | $410,001–less than $750,000 | $649.201 | $83.301 |
| $500,000 or more | $750,000 or more | $689.901 | $91.001 |
Source: CMS 2026 Medicare Parts A & B premiums and deductibles fact sheet.1 Part D IRMAA is added to the beneficiary’s plan premium. Married individuals who file separately and lived with their spouse at any time during the year face different brackets: $0 IRMAA at $109,000 or less, a $649.20 total Part B premium from $109,001 to less than $391,000, and $689.90 at $391,000 or more (Part D: $83.30 and $91.00).1 Figures apply to 2026 and are subject to annual change.
The Cliff Effect: Why One Dollar Can Matter
IRMAA brackets operate as thresholds, not as a gradual phase-in. Under the 2026 table, an individual filer with MAGI of $109,000 pays no IRMAA, while MAGI of $109,001 moves the filer into the first tier, with an $81.20 Part B adjustment and a $14.50 Part D adjustment.1 By our calculation, that is $95.70 per month, or $1,148.40 for the year, triggered by one additional dollar of income.1
The hypothetical illustration below applies the 2026 schedule to a single filer with $100,000 of other MAGI who is considering different conversion amounts.1
| Roth Conversion Amount | Resulting MAGI | Monthly IRMAA (Part B + Part D) | Annual IRMAA |
|---|---|---|---|
| $0 | $100,000 | $0.00 | $0.00 |
| $9,000 | $109,000 | $0.00 | $0.00 |
| $9,001 | $109,001 | $95.70 | $1,148.40 |
| $40,000 | $140,000 | $240.40 | $2,884.80 |
Assumptions: single filer; $100,000 of other MAGI; the entire conversion is taxable; 2026 IRMAA amounts from CMS applied for illustration (Part B adjustments of $81.20 and $202.90; Part D adjustments of $14.50 and $37.50).1 Actual premiums would be set two years after the conversion year using the brackets in effect then.3 Annual figures are monthly amounts times 12, by our calculation.
This is a hypothetical situation used for education purposes only. The information does not represent a current client, and the results shown are hypothetical — they do not reflect actual results achieved by any client and are not a guarantee of future performance. Actual results will vary based on an individual’s specific circumstances.
Planning Considerations Before Converting
The points below are educational and may or may not apply to a given household; tax, cash-flow, and estate factors also bear on conversion decisions.
Know the reference year. Because the determination generally looks back two years, conversion income is generally evaluated against brackets that will apply two years later.3
Consider the pre-Medicare window. Income in years more than two years before Medicare enrollment generally falls outside the lookback for the first premium year, so some households evaluate conversions in their early 60s.3
Measure headroom to the next threshold. Estimating MAGI, including tax-exempt interest, before converting can show how much room remains below a bracket edge.1,2
Weigh spreading versus concentrating. Smaller conversions over several years may keep each year within a lower tier, while a single large conversion may cross several tiers for one premium year.1,3
Account for filing status changes. Married individuals filing separately who lived with their spouse face a much narrower set of brackets.1
Can You Appeal IRMAA After a Roth Conversion?
Form SSA-44 allows a beneficiary to request a new IRMAA determination when MAGI has dropped because of a qualifying life-changing event.2,5 The regulations list these events: death of a spouse, marriage, divorce or annulment, work stoppage or reduction, loss of income-producing property under specified circumstances, scheduled cessation or reorganization of an employer pension plan, and certain employer settlement payments.3
The regulations state that Social Security “will not consider events other than those” listed.3 A voluntary Roth conversion is not on the list, so it does not by itself support an SSA-44 request.3,5 However, if a conversion happened in the same year as a qualifying event, such as retirement, the work stoppage may be the basis for a request, with documentation and the related tax return or an estimate.5 Separately, a beneficiary who believes Social Security used incorrect tax data may contact Social Security to update records.2
Frequently Asked Questions
Yes, the taxable portion does. The IRS states that a Roth conversion results in taxation of any untaxed amounts in the traditional IRA, and Social Security defines MAGI for IRMAA as adjusted gross income plus tax-exempt interest income.2,4
Generally one premium year per conversion year. Social Security generally uses MAGI from the tax year two years before the premium year, so a 2026 conversion would generally affect 2028 premiums, and IRMAA is redetermined each year from the applicable tax year.2,3
For 2026, IRMAA begins above $109,000 of MAGI for individual filers and above $218,000 for joint filers, with higher tiers starting at $137,001, $171,001, $205,001, and $500,000 for individuals and $274,001, $342,001, $410,001, and $750,000 for joint filers.1
Not on the basis of the conversion alone. Federal regulations list the qualifying life-changing events and state that other events will not be considered; a voluntary conversion is not listed.3 A separate qualifying event in the same period, such as stopping work, may support a request.5
Yes. For 2026, Part D IRMAA ranges from $14.50 to $91.00 per month, depending on MAGI, and is added to the beneficiary's plan premium. The Part D income thresholds match the Part B thresholds.1
Where This Fits Into a Broader Financial Plan
Roth conversion decisions can touch income taxes, Medicare premiums, estate plans, and cash flow at the same time. As a fee-only fiduciary, Moran Wealth Management receives no commissions or product incentives, and we coordinate with each client’s CPA, attorney, and other professionals so that projections reflect the full picture. We do not provide legal or tax advice directly. Each professional retains responsibility for their own advice and work, and results can vary based on individual circumstances.
If you would like to review how a conversion strategy may interact with your Medicare premiums, we invite you to schedule a complimentary consultation.
Call 239-920-4440, or email info@moranwm.com.
Sources
[1] 2026 Medicare Parts A & B Premiums and Deductibles, Centers for Medicare & Medicaid Services
[2] Medicare Premiums (Rules for Higher-Income Beneficiaries), Social Security Administration
[3] 20 CFR Part 418, Subpart B: Medicare Part B Income-Related Monthly Adjustment Amount, Electronic Code of Federal Regulations
[4] Retirement Plans FAQs Regarding IRAs, Internal Revenue Service
[5] Form SSA-44: Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event, Social Security Administration
This commentary is for informational purposes only and does not constitute investment advice, a recommendation, or an offer or solicitation to buy or sell any securities. The views expressed are those of the author(s) as of the date of publication and are subject to change without notice. Past performance is not indicative of future results.
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