Utah · IRMAA and retirement income

Will a Roth Conversion Raise My Medicare Premiums in Utah?

Yes, if the conversion lifts your income past $109,000 on a single return or $218,000 on a joint one. The surcharge starts at $95.70 a month per person for Part B and Part D together, it arrives two years after the conversion, and it lasts one year. Utah adds its own cost: 4.45% income tax on the converted amount and a smaller Social Security credit. Here is the arithmetic for two Utah households.

Medicare On Main Data Desk

Published September 29, 2026 · 10 min read · Reviewed by Brian Penner, 22+ years in Medicare

Year-end is when many people decide on a conversion, and it is when I hear this question from Utah clients and their financial advisors. The conversion itself is a tax decision, and it belongs with your tax advisor. The Medicare premium is the part I can explain, because it follows a published table.

Start with the income. IRS Publication 590-A says, "You must include in your gross income distributions from a traditional IRA that you would have had to include in income if you hadn't converted them into a Roth IRA." The converted amount is in your adjusted gross income for that year.

Medicare then uses that figure. Under 20 CFR § 418.1010, its income measure is "your adjusted gross income as defined by the Internal Revenue Code, plus" tax-exempt interest and four rarer items. Under § 418.1135, Social Security uses "the tax year 2 years prior to the effective year." So the conversion you do this December appears in your premium in January 2028.

The 2026 table, and how much room you have

Source: CMS: 2026 Medicare Parts A & B Premiums and Deductibles (Nov 14, 2025). 2026 premiums, based on 2024 income. The surcharges are added to the standard Part B premium of $202.90 and to your drug plan's premium. The last column is our arithmetic: the two monthly amounts, times twelve.

The lines move up each year. The 2027 Medicare handbook prints the next one: "in 2027 it's $111,000 if you file individually or $222,000 if you're married and file jointly." That applies to 2025 income. The 2028 table, which is the one a 2026 conversion is measured against, has not been published. CMS announces each year's amounts the November before.

Because the 2028 line is not known, leave a margin. A year-end fund distribution or a larger-than-expected dividend lands in the same adjusted gross income, and being one dollar over costs the full tier.

A Utah couple near the line

These are stated assumptions, not a client. A couple in their late sixties, both on Medicare, files jointly with $190,000 of modified adjusted gross income from a pension, IRA withdrawals and Social Security. They convert $50,000.

Our arithmetic from the CMS 2026 table and Utah Code § 59-10-104. Federal income tax on the conversion is separate and depends on the couple's bracket.

The Medicare surcharge works out to 4.6% of the amount converted. It is a real cost, and it is a one-time cost. Whether it is worth paying depends on the tax they expect to avoid later, and that is the question for their tax advisor. The part I would point out is the $28,000. A couple who converts that much this year and the rest next year may pay no surcharge in either year.

The Utah layer

Utah has no separate treatment for a Roth conversion. Under Utah Code § 59-10-103, adjusted gross income "means the same as that term is defined in Section 62, Internal Revenue Code," and state taxable income starts from it. The rate in § 59-10-104 is 4.45% for 2026.

The second effect is on the state's Social Security credit. Utah Code § 59-10-1042 gives a credit equal to the tax rate times the Social Security benefit included in your state taxable income. The credit "shall be reduced by $.025 for each dollar by which modified adjusted gross income for purposes of the return exceeds" $54,000 on a single return or $90,000 on a joint one. A conversion raises that income.

Here is a second couple, again with stated assumptions. They have $100,000 of income, including $40,000 of Social Security of which $34,000 is taxable. They convert $40,000.

Our arithmetic from Utah Code § 59-10-1042 and § 59-10-104. The taxpayer tax credit in § 59-10-1018 is also reduced, by 1.3 cents per dollar of state taxable income over an indexed amount, and is not included here.

This couple owes no Medicare surcharge. At $140,000 they are well under $218,000. Their cost is on the Utah return. The first couple has the opposite result. At $190,000 their credit had already been reduced by $2,500, which erases the credit on about $56,000 of taxable benefits. The conversion costs them the plain 4.45% in Utah and the surcharge from Medicare.

Four lines a conversion can cross

Sources: CMS 2026 fact sheet; Medicare & You 2027; Utah Code § 59-10-1042; IRS, deduction for seniors; 26 U.S.C. § 86. Each line uses its own definition of income, so have your tax preparer run the return both ways.

Medicare's line gets the attention, and on a joint return it is the highest of the four. A conversion planned only around $218,000 can still cost more than expected at $90,000 and $150,000.

Which conversion year touches which premium year

Sources: 20 CFR § 418.1135 for the two-year lookback; IRS Publication 590-A: "You can't convert amounts that must be distributed from your traditional IRA for a particular year (including the calendar year in which you reach age 73)."

The table assumes Medicare at 65. If you are still working at 63 and 64, your wages may already put you over the line in those years, and a conversion adds to it. If you retire at 65, the drop in wages is a life-changing event you can report. We cover that in how to appeal IRMAA after retirement.

You cannot undo it, and you cannot appeal it

Before 2018 a conversion could be reversed if the numbers came out wrong. That option is gone. Publication 590-A says a conversion "made in tax years beginning after December 31, 2017, cannot be recharacterized as having been made to a traditional IRA." The amount you convert in December is final.

The appeal route is narrow too. 20 CFR § 418.1205 lists seven major life-changing events, and § 418.1210 says, "We will not consider events other than those described in § 418.1205." A conversion is not among them. So the planning has to happen before the conversion.

Does the surcharge follow you into a Medicare Advantage plan?

Yes. IRMAA is attached to Part B and Part D, and you keep Part B in any Medicare Advantage plan. A plan with a $0 premium does not remove the surcharge, and a Medigap policy does not pay it. We go through that in do you pay IRMAA on a Medicare Advantage plan.

What I would do

1. Find your starting point. Add line 11 and line 2a of last year's Form 1040. Estimate this year's the same way.
2. Measure the room to the next threshold, and leave a margin for year-end distributions.
3. Ask your tax preparer to run the Utah return too. The Social Security credit and the taxpayer credit both shrink as income rises.
4. Consider two smaller conversions across two tax years when one large one would cross a line.
5. Decide with your tax advisor. A year of surcharge can be worth paying. It should be a choice and not a surprise in a letter from Social Security.

Whatever the premium, the coverage decision is separate. In Grand County, 33.3% of adults live with high blood pressure and 11.2% with diabetes, per CDC PLACES. The plan's network and drug list decide what your care costs, and the surcharge is the same under any of them.

How we know all this: the Medicare On Main Data Desk frames every article with public data — here, IRS Publications 590-A and 590-B for the conversion and Roth distribution rules, quoted as published; 20 CFR §§ 418.1010, 418.1135, 418.1205 and 418.1210 for Medicare's income measure, the two-year lookback and the life-changing events; the CMS fact sheet of November 14, 2025 for every 2026 amount; the 2027 Medicare & You handbook for the 2027 threshold; the IRS for the deduction for seniors; Utah Code §§ 59-10-103, 59-10-104, 59-10-1018 and 59-10-1042 as in effect for 2026; and CDC PLACES county data (2023). Both households are worked examples with stated assumptions, not clients, and federal income tax is not calculated. No product, company or rate of return is named. We are licensed insurance agents, not tax advisors. This is education, not advice; review a conversion with your tax advisor, and confirm plans, costs and eligibility with a licensed agent or Medicare.gov. We take no payment from any carrier to feature a plan.