Can a Roth Conversion Affect IRMAA? 2026 Medicare Brackets Explained

IRMAA means Income-Related Monthly Adjustment Amount. Beneficiaries whose MAGI exceeds the applicable threshold may pay an additional amount with Medicare Part B and an additional amount for Medicare prescription-drug coverage. The Part D IRMAA is added to the person’s separate Part D plan premium; it is not the plan premium itself. [1] [2]

The adjustment changes what a beneficiary pays for the coverage. It does not create a different benefit package, and it is not an income-tax surcharge. Someone enrolled in Part B but not Part D can owe only the Part B adjustment; someone enrolled in both can owe both.

Generally, the taxable portion does. IRS guidance says a traditional IRA amount that would have been included in income if distributed is generally included in gross income for the year it is converted. Because that amount generally affects AGI, it can also affect IRMAA MAGI. SSA defines IRMAA MAGI as AGI plus tax-exempt interest. [3] [8]

The gross amount moved and the taxable amount are not always identical. Valid nondeductible traditional IRA basis represents money already taxed and may make part of a conversion nontaxable. The calculation generally considers applicable Traditional, SEP, and SIMPLE IRA balances, so an account label alone does not establish the nontaxable amount.

Form 8606 is used to report nondeductible contributions, certain IRA distributions, and conversions from Traditional, SEP, or SIMPLE IRAs to Roth IRAs. [9] Review the Agent Roth explanation of how Roth conversions are taxed and the FAQ answer on IRA basis and Form 8606 before assuming every converted dollar increases MAGI.

SSA generally uses the most recent federal tax information the IRS can provide, commonly from two years before the premium year. For 2026, that is generally a return filed in 2025 for tax year 2024. [2] [3]

If two-year-old data is unavailable, the IRS may return information from three years earlier. SSA can later update the determination when appropriate information becomes available. [4]

The standard 2026 Part B premium is $202.90 per month. The table below uses CMS figures for full Part B coverage and Part D IRMAA. The Part D amount is added to the beneficiary’s ordinary plan premium. These 2026 premiums generally use 2024 tax-return information.

CMS published these 2026 full Part B and Part D figures on November 14, 2025. [1] SSA also presents the general 2024-income lookback and current premium table. [2]

This married-filing-separately table applies when the beneficiary lived with the spouse at some time during the taxable year. Other filing and living arrangements require the applicable SSA table; they should not be collapsed into this special table.

Consider an illustrative married couple filing jointly. Both spouses are enrolled in Part B and Part D. Their 2024 MAGI before a taxable conversion is $210,000. A $15,000 taxable conversion produces a simplified MAGI of $225,000. Because the first 2026 joint threshold is $218,000, the example falls in Tier 1.

Actual enrollment status matters. MAGI may contain wages, pensions, gains, interest, tax-exempt interest, taxable Social Security, deductions reflected in AGI, and other items. The conversion’s taxable amount may differ from the gross transfer. This example illustrates tier mechanics; it does not recommend reducing, avoiding, or completing a conversion.

IRMAA is bracketed. Crossing a threshold can place a beneficiary in the next monthly surcharge tier rather than applying a percentage only to the income above the threshold. That step-up is why a relatively small MAGI difference can change a full year of monthly adjustments.

Projected MAGI is still an estimate. Taxable conversion amount, IRA basis, capital gains, interest, tax-exempt interest, taxable Social Security, business income, and other adjustments may move the final return. A narrow cushion can disappear when another income item changes.

Remaining below a threshold is not automatically the best financial outcome. A household may reasonably accept higher premiums as one cost inside a broader retirement-tax plan. The comparison can include current income tax, future distributions, account flexibility, estate goals, available tax cash, and the duration of any premium effect.

Generally, no—not under the normal two-year lookback. A 2026 conversion affects the 2026 tax year, while a standard 2026 IRMAA determination generally uses 2024 income. The taxable 2026 conversion would generally become relevant for 2028 premiums.

That does not mean the 2028 result can be calculated today. Future thresholds, the standard Part B premium, Part D adjustments, tax-return information, filing status, and enrollment may differ. The 2026 figures are current facts for 2026 premiums, not a forecast.

Yes, when a joint return supplies the MAGI and both spouses are enrolled in the affected Medicare coverage. IRMAA is charged per Medicare beneficiary. If both spouses have Part B and Part D, each may owe both adjustments at the joint-return tier.

If only one spouse is enrolled in Part B, only that beneficiary pays the Part B adjustment. The same coverage-specific rule applies to Part D. Filing status and living arrangements determine which threshold table applies, so married filing separately should not be treated as ordinary “individual” filing without checking the SSA rules.

A Roth conversion alone generally is not one of the qualifying life-changing events for an SSA-44 request. SSA’s list of qualifying events is exclusive, and SSA notices explain that MAGI may contain one-time income such as an IRA withdrawal or traditional-to-Roth conversion. [6] [7]

A beneficiary may have a separate qualifying event: marriage; divorce or annulment; death of a spouse; work stoppage; work reduction; certain loss of income-producing property; certain loss or reduction of employer pension income; or certain employer settlement payments. A genuine event that reduces household income may support a request for SSA to use more recent information, but SSA evaluates the facts and evidence.

Different processes address different problems. A qualifying event may support a new initial determination. Inaccurate IRS information can be corrected. An amended return can be reported to SSA. A person who disagrees with SSA’s determination can use the appeal process. Filing Form SSA-44 does not guarantee a reduction. [2] [5]

Stopping work or reducing work hours can be a qualifying life-changing event when it reduces income. The work change—not the conversion—is the event. SSA considers the request, supporting evidence, and newer MAGI information under its process.

Retirement does not automatically remove conversion income from MAGI. If a beneficiary provides an updated income estimate that includes a large taxable conversion, that conversion may still be part of the newer MAGI. The request needs to reflect the full expected income picture rather than wages alone.

Income generally matters for a premium year two years later, so someone approaching Medicare may want to map each planned conversion year to the first possible premium year. A conversion completed more than two years before enrollment may fall outside the ordinary lookback for the first Medicare premium year, but exact enrollment timing and available IRS data matter.

Age 63 is often discussed because income from approximately two years earlier may be used when Medicare begins. It is not a universal deadline. The useful window depends on enrollment timing, tax years, available data, filing status, and the household’s full circumstances. Compare the related guides on conversions before Social Security and before required minimum distributions without assuming either window dictates a transaction.

Use this educational lookup to compare a 2024 MAGI with the exact CMS 2026 table. It estimates only the incremental Part B and Part D IRMAA for the selected enrollment counts. It does not determine taxable conversion income or produce an official SSA premium decision.

1. Which tax year will contain the conversion?
2. Which Medicare premium year could use that tax return?
3. What is projected AGI before the conversion?
4. How much tax-exempt interest is expected?
5. What portion of the conversion is expected to be taxable?
6. Is there valid nondeductible IRA basis?
7. Are capital gains or other large income items expected?
8. Will one or both spouses be enrolled in Part B?
9. Will one or both spouses be enrolled in Part D?
10. Which filing-status table applies?
11. Is a genuine SSA life-changing event expected?
12. Could an amended return or corrected IRS information become relevant?
13. How does the conversion fit into the broader retirement-tax plan?

These questions organize the calculation; they do not identify a conversion amount. A current tax projection and the household’s complete retirement plan may be needed to compare the tradeoffs.

• The taxable portion of a conversion can increase AGI.
• IRMAA MAGI generally includes AGI plus tax-exempt interest.
• Medicare generally looks back two tax years.
• A 2024 conversion may affect 2026 premiums.
• A 2026 conversion would generally be relevant to 2028 premiums.
• A Roth conversion alone is generally not an SSA-44 qualifying life-changing event.

For evergreen mechanics, read the Roth conversion and IRMAA guide. For the timing of the related tax payment, review the current Brief on when Roth conversion taxes are due.