How Do Roth Conversions Affect IRMAA and Medicare Part B Premiums?
Last reviewed: July 2026
A Roth conversion can raise your Medicare premiums two years later by pushing your modified adjusted gross income (MAGI) into a higher IRMAA bracket. IRMAA, the Income-Related Monthly Adjustment Amount, is a surcharge added to your Medicare Part B and Part D premiums once your income crosses certain thresholds. Because Medicare uses a two-year lookback, the IRMAA roth conversion you complete at 63 can increase what you pay at 65. The good news: with planning, you can convert strategically and stay under the brackets that matter.
Key Takeaways
- IRMAA uses a two-year lookback, so a Roth conversion today can raise your Medicare premiums two years from now.
- The 2026 standard Medicare Part B premium is $202.90 per month, per CMS.
- IRMAA is a cliff, not a phase-in: one dollar over a threshold can cost you hundreds per year.
- Converting before you enroll in Medicare, or in lower-income years, helps you avoid the surcharge entirely.
About the Author: Jeff Judge, CFP®, AEP®, ChFC®, CLU® is Managing Partner of Chesapeake Financial Planners in Forest Hill, Maryland. He has been helping families and business owners in Harford County and the Baltimore metro area navigate Roth conversions and Medicare planning since earning his CFP® certification in 2013, by using Chesapeake Financial Planners’ signature process, the R.U.D.D.E.R. method™. Jeff sees the same mistake every fall: a client does a large conversion in December without checking the IRMAA math, then gets a surprise letter from Social Security two years later.
What Is IRMAA and How Does It Work?
IRMAA is a surcharge that Medicare adds to your monthly Part B and Part D premiums when your income exceeds set thresholds. It stands for Income-Related Monthly Adjustment Amount, and it applies on top of the standard premium everyone pays. In 2026, the standard Part B premium is $202.90 per month according to CMS, with an annual deductible of $283.
The income figure IRMAA uses is your MAGI: your adjusted gross income plus any tax-exempt interest. The Social Security Administration administers the surcharge and notifies you by mail if you owe it. Here is the part that catches people. IRMAA is determined using your tax return from two years prior. Your 2026 premium is based on your 2024 MAGI.
IRMAA is a cliff, not a gradual ramp. Cross a threshold by a single dollar and you pay the full surcharge for that entire bracket. That structure is exactly why Roth conversions and IRMAA need to be planned together, not separately.
How Does a Roth Conversion Trigger IRMAA?
A Roth conversion adds the converted amount to your taxable income for the year, which raises your MAGI. If that higher MAGI crosses an IRMAA threshold, you pay the surcharge two years later. This is the IRMAA roth conversion trap, and it surprises people because the bill arrives long after the conversion.
Say you convert $80,000 in 2024 to take advantage of a low-income year. That conversion counts as ordinary income, lifting your MAGI. If it pushes you over a bracket, your 2026 Medicare premiums climb. You already paid the income tax on the conversion. Now you pay a premium surcharge on top of it.
The two-year lag is what makes this easy to miss. By the time the higher premium hits, the conversion feels like ancient history. Jeff has watched clients absorb an extra $1,000 to $2,000 in annual Medicare costs they never saw coming, simply because no one mapped the conversion against the brackets first. He keeps a one-page IRMAA grid on his desk for this exact reason. It is faster to check the bracket before a conversion than to explain the surcharge afterward.
Should I Do Roth Conversions Before I Retire?
What Are the 2026 IRMAA Thresholds?
The 2026 IRMAA brackets are based on your 2024 MAGI and apply to both Part B and Part D. There are six income tiers, and the surcharge grows at each one. The table below shows the Part B figures for individuals and married couples filing jointly, per CMS.
| 2024 MAGI (Individual) | 2024 MAGI (Married Filing Jointly) | 2026 Total Monthly Part B Premium |
|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 (standard) |
| $109,001 – $137,000 | $218,001 – $274,000 | $284.10 |
| $137,001 – $171,000 | $274,001 – $342,000 | $405.80 |
| $171,001 – $205,000 | $342,001 – $410,000 | $527.50 |
| $205,001 – $500,000 | $410,001 – $750,000 | $649.20 |
| Above $500,000 | Above $750,000 | $689.90 |
Each tier also adds a separate Part D surcharge on top of your drug plan premium. The jump from the standard premium to the top bracket is significant. A high earner can pay roughly $5,800 more per year for Part B alone. Notice the brackets are not evenly spaced, which matters when you decide how much to convert.
How Can You Convert Without Triggering IRMAA?
The cleanest strategy is to do your Roth conversions before you enroll in Medicare, ideally in your early 60s, when MAGI does not yet affect Medicare premiums. Conversions done at 63, 64, or 65 still feed the two-year lookback, so the planning window is narrower than most people assume. This is where coordinating the conversion timeline with your Medicare start date pays off.
For clients already on Medicare, the approach shifts to fitting conversions inside the bracket you can tolerate. If you can convert $40,000 this year without crossing the next threshold, you capture some Roth benefit while keeping the surcharge flat. Partial conversions across several years often beat one large conversion that blows through two brackets at once.
At Chesapeake Financial Planners, we run this analysis using the R.U.D.D.E.R. Method™, our six-step planning process: Review and Recognize, Uncover and Understand, Design and Develop, Discuss and Decide, Execute and Empower, and Reassess and Refine. Mapping the conversion against the IRMAA brackets, the tax brackets, and the Medicare timeline together is the only way to avoid an expensive surprise.
There is also relief if your income drops because of a life event. The Social Security Administration lets you appeal IRMAA after qualifying events such as retirement, divorce, or the death of a spouse using Form SSA-44. That appeal does not cover a voluntary Roth conversion, though, which is exactly why the conversion deserves planning up front.
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What Are the Different Parts of Medicare and What Do They Cover?
Frequently Asked Questions
Does a Roth conversion count toward IRMAA income?
Yes. A Roth conversion adds the full converted amount to your taxable income, which increases your modified adjusted gross income. Since IRMAA brackets are based on MAGI, a large conversion can push you into a higher tier and raise your Medicare Part B and Part D premiums two years later.
How many years does IRMAA look back at my income?
IRMAA uses a two-year lookback. Your Medicare premiums in a given year are based on the tax return you filed two years earlier. For example, your 2026 IRMAA surcharge is determined by your 2024 modified adjusted gross income, which is why conversions need to be planned well in advance of enrolling.
What is the IRMAA income threshold for 2026?
For 2026, the first IRMAA threshold is $109,000 in MAGI for individuals and $218,000 for married couples filing jointly, based on 2024 income, per CMS. Cross that line and your Part B premium rises above the standard $202.90 per month. Higher income crosses additional brackets, up to a top tier.
Can I appeal an IRMAA surcharge caused by a Roth conversion?
No, a voluntary Roth conversion is not a qualifying event for an IRMAA appeal. The Social Security Administration allows appeals using Form SSA-44 only after life-changing events such as retirement, divorce, or a spouse's death. A planned conversion does not qualify, which is why timing it correctly upfront matters so much.
Is it better to convert before or after enrolling in Medicare?
Converting before you enroll in Medicare is generally better for avoiding IRMAA, but the two-year lookback means conversions in your early 60s can still affect premiums at 65. The cleanest window is usually before age 63. After enrollment, partial conversions sized to stay under a bracket are the safer approach.
How much does IRMAA add to my Medicare premiums?
IRMAA adds roughly $81 to $487 per month to your Part B premium in 2026, on top of the standard $202.90, depending on your income tier, per CMS. A separate Part D surcharge applies as well. At the top bracket, IRMAA can add several thousand dollars to your annual Medicare costs.
Plan the Conversion and the Premium Together
A Roth conversion and your Medicare premiums are two sides of the same decision, and treating them separately is how people get caught. The math is knowable. You just have to run an IRMAA roth conversion analysis before you convert, not after the surcharge letter shows up. If you want to see how Roth conversions fit into a broader retirement income plan, our guide on tax-smart retirement strategies walks through the timing in detail. Download it at chesapeakefp.com.
Roth conversions have specific tax implications and may not be suitable for all investors. The decision to convert traditional retirement assets to a Roth should be made in consultation with a qualified tax professional based on your individual circumstances.
Want to go deeper? Our Tax Strategy Readiness Quiz walks through this step by step.
Disclosures
The information provided is for educational purposes only and should not be construed as investment advice. Investment strategies should be tailored to individual circumstances, risk tolerance, and goals. Past performance doesn't guarantee future results. Consult with qualified financial professionals regarding your specific situation.
Traditional IRA account owners have considerations to make before performing a Roth IRA conversion. These primarily include income tax consequences on the converted amount in the year of conversion, withdrawal limitations from a Roth IRA, and income limitations for future contributions to a Roth IRA. In addition, if you are required to take a required minimum distribution (RMD) in the year you convert, you must do so before converting to a Roth IRA.
A Roth IRA offers tax deferral on any earnings in the account. Qualified withdrawals of earnings from the account are tax-free. Withdrawals of earnings prior to age 59 ½ or prior to the account being opened for 5 years, whichever is later, may result in a 10% IRS penalty tax. Limitations and restrictions may apply.
Advisors associated with Chesapeake Financial Planners may be either (1) LPL Financial Registered Representatives offering securities through LPL Financial, Member FINRA and SIPC, and investment advisor representatives offering investment advice through Great Valley Advisor Group; or (2) solely investment advisor representatives offering investment advice through Great Valley Advisor Group and not affiliated with LPL Financial. Great Valley Advisor Group, and Chesapeake Financial Planners are separate entities from LPL Financial.
