IRMAA-Aware Roth Conversions: How to Cut Lifetime Taxes Without Getting Blindsided by Medicare Premiums

A Roth conversion moves money from a pre-tax account - a traditional IRA, 401(k), or 403(b) - into a Roth IRA. You pay ordinary income tax on the converted amount in that year. In exchange, qualified Roth IRA withdrawals are generally tax free for the rest of your life. Roth IRAs also carry no lifetime RMDs, which means your Roth account can continue compounding without forced distributions.

Conversions reduce your traditional IRA balance, which directly reduces future required minimum distributions. Smaller RMDs mean lower taxable income in your 70s and 80s, lower federal tax, lower state tax, and less exposure to IRMAA thresholds. For heirs, Roth balances inherited under the SECURE Act's 10-year rule can be far more valuable than pre-tax dollars.

One important wrinkle: since the Tax Cuts and Jobs Act eliminated recharacterizations after 2017, Roth conversions are irrevocable. You cannot undo one. That is exactly why careful modeling - running side-by-side scenarios of converting versus not converting - matters before a single dollar moves. Revolutionary Wealth routinely runs these projections, estimating lifetime taxes, RMDs, and medicare costs under multiple paths. Learn more about when moving from a traditional IRA to a Roth IRA makes sense.

An Income-Related Monthly Adjustment Amount (IRMAA) is a surcharge added on top of standard Medicare Part B and Part D premiums for higher income beneficiaries. IRMAA is based on the Modified Adjusted Gross Income from two years prior. Your 2024 tax return drives your 2026 premiums; your 2026 return drives 2028.

MAGI for this purpose includes adjusted gross income plus tax exempt interest income. That means wages, pension income, traditional IRA distributions, Roth conversion amounts, capital gains, rental income, investment income, the taxable portion of Social Security, and even tax exempt interest from municipal bonds all count. Qualified Roth IRA withdrawals after meeting age and holding-period requirements do not.

Here is the part that catches people off guard. IRMAA brackets operate as strict thresholds without pro-rata scaling. There is no gradual phase-in. Exceeding an IRMAA threshold by one dollar triggers the full surcharge for the entire premium year. This IRMAA cliff means a $1 overshoot over the threshold can cost a married couple approximately $2,297 in extra Medicare premiums per year. IRMAA surcharges are temporary in the sense that they apply for one year based on income from two years prior, but they recur every year your MAGI stays elevated.

The two-year lookback rule affects how Roth conversions impact Medicare premiums in a way most people do not anticipate. If you turn 65 in 2028, Medicare looks at your 2026 tax return - the year you were 63 - to set your first-year Part B premiums. A Roth conversion performed in one year can affect Medicare premiums two years later, and that first bill can be a shock.

This timing creates what advisors call the "golden window." Roth conversions executed before age 65 can build tax free assets without triggering IRMAA, provided the conversions happen early enough. Specifically, Roth conversions are optimal before age 63 to avoid IRMAA on your initial Medicare enrollment. A couple retiring at 60 who converts aggressively from ages 60 to 62 can shrink future RMDs and IRMAA exposure without any Medicare premium impact at all - because Medicare has not started yet and those conversion years fall outside the lookback window for their age-65 enrollment.

Revolutionary Wealth builds timeline-based plans showing exactly which future Medicare years are affected by each year's Roth conversion decisions. No guessing, no surprises.

IRMAA thresholds are structured separately for single filers and married filing jointly couples. They are distinct from federal income tax brackets but interact with them. Below is a simplified table for 2026 premiums (based on 2024 MAGI):

The Medicare Part B standard premium for 2026 is $202.90 per month. Single filers face a 2026 IRMAA threshold of $109,000. IRMAA surcharges for 2026 range from $81.20 to $487.00 monthly. For married couples, IRMAA is assessed per person - meaning both spouses pay the surcharge, effectively doubling the cost of crossing a bracket. Exceeding IRMAA thresholds can cost thousands in extra Medicare premiums each year.

Every dollar converted from a traditional IRA to a Roth increases taxable income and MAGI dollar-for-dollar in the conversion year. Higher MAGI flows directly into the IRMAA calculation two years later.

Consider a married filing jointly couple with $120,000 in baseline MAGI from Social Security benefits, pension, and other income. A $100,000 Roth conversion pushes their total income to $220,000 - just over the $218,000 IRMAA threshold. That triggers the first IRMAA tier for both spouses, adding roughly $81 per person per month in Part B premiums plus Part D surcharges. That one conversion could mean $2,000 to $3,000 in extra Medicare premiums for that premium year alone.

But here is the other side: by converting that $100,000, they have permanently reduced their traditional IRA balance. Their future RMDs will be smaller. Taxable Social Security may be lower. And their long term tax savings - measured over 20+ years - can dwarf those few years of higher Part B premiums. Roth conversions can reduce future required minimum distributions significantly, which is the whole point of this exercise. Revolutionary Wealth's IRA and 401(k) planning tools explicitly model the Roth conversion amount alongside IRMAA brackets and federal income tax brackets to find the right balance.

The formula for an IRMAA-aware conversion ceiling is straightforward:

Maximum conversion = Target IRMAA threshold – Projected baseline MAGI (without conversions)

For a married filing jointly couple in 2026 with baseline MAGI of $150,000 (from Social Security, pension income, and investment income), the first IRMAA threshold sits at $218,000. Their conversion ceiling is $68,000 - the optimal Roth conversion amount that avoids any surcharge that year.

But this formula must be cross-checked against the tax bracket ceiling. If converting $68,000 would push them beyond the 22% bracket into the 24% bracket, you may want to cap the conversion at the lower of the two ceilings. Spreading a Roth conversion over multiple years helps manage both income thresholds and taxes - rather than one massive conversion that blows through multiple income tax brackets and IRMAA tiers.

Do major conversions in the fall when dividends, capital gains, and other income are more predictable. Leave a buffer under the IRMAA threshold. Revolutionary Wealth uses cutting-edge tax and income software to calculate this conversion ceiling annually, testing paths of no IRMAA, limited IRMAA, and intentionally higher IRMAA to find the best lifetime outcome. Book a call if you want to see your own numbers.

If a couple has $2 to $3 million in traditional IRAs plus two Social Security benefits and a pension, their future RMDs alone may permanently push gross income above IRMAA thresholds. A married filing jointly couple age 73 with $2 million in traditional IRAs could face six-figure RMDs. Add Social Security and pension income and they are locked into at least the first IRMAA tier for life - even without a single Roth conversion.

The mindset shift matters: the goal is not "never pay IRMAA." The goal is to pay IRMAA intentionally for fewer years and on lower balances. Compare two paths:

• Path A - No conversions: Face 15 to 20 years of high RMDs, escalating tax burden, and IRMAA surcharges that compound year after year.

• Path B - Focused conversions in your 60s: Accept IRMAA for 3 to 7 years, pay taxes at today's lower tax brackets, and emerge with smaller RMDs and potentially no IRMAA from your mid-70s onward.

Path B often wins by six figures in lifetime taxes and Medicare costs. Revolutionary Wealth's modeling shows families the projected total tax bill plus Medicare IRMAA premiums under each strategy across their full retirement. Learn how we approach this in our RMD planning guide.

Not all years are equal for conversions. Here are the windows worth targeting:

• Ages 60–63 (pre-Medicare): With little or no earned income, no Social Security, and no RMDs, total income is often at its lowest. You can fill lower tax brackets with conversions and build tax free assets before IRMAA even enters the picture.

• Ages 66–72 (post-Social Security, pre-RMD): Income rises from benefits, but RMDs have not started. There is still room to maneuver below IRMAA thresholds with careful sizing.

• While both spouses are alive: After one spouse dies, the survivor shifts from married filing jointly to single. IRMAA thresholds drop roughly in half. Federal income tax brackets tighten. This "widow's penalty" makes conversions while both are alive - using the wider MFJ thresholds - far more attractive.

• Low-income gap years: A year between consulting contracts, a large medical deduction, or a business transition can create temporary space for bigger conversions at a lower tax rate.

Revolutionary Wealth's retirement income planning process maps these windows and coordinates Social Security timing, pension elections, and IRA withdrawals to open maximum conversion room.

Meet John and Maria, both 62, married filing jointly, with $1.8 million in traditional IRAs, $250,000 in taxable accounts, no pensions, and plans to claim Social Security at 67.

Scenario 1 - Stay under IRMAA each year. They convert $50,000 to $65,000 annually from ages 62 to 72, keeping MAGI under $218,000. RMDs start smaller at 73 but still push them into the first income tier by their late 70s. IRMAA exposure: roughly 10 to 15 years.

Scenario 2 - Accelerated conversions, accept short-term IRMAA. From 62 to 66 they convert $120,000 to $150,000 per year, intentionally crossing into the first or second IRMAA tier. They pay taxes in the 22% and 24% brackets. Medicare premiums are higher for a few years. But by 73 their traditional IRA balance is dramatically smaller - RMDs are modest - and they stay below IRMAA thresholds for the remainder of their lives.

By accepting roughly $3,000 to $6,000 per year in IRMAA surcharges for 4 years, John and Maria reduce projected lifetime taxes and Medicare premiums by an estimated six-figure amount. The optimal Roth conversion path varies by family, but Revolutionary Wealth's modeling process is designed to surface exactly these trade-offs before any conversion is executed.

Medicare IRMAA is only one constraint. Roth conversion decisions also interact with federal income tax brackets, the 3.8% Net Investment Income Tax, state taxes, and Social Security taxation.

Conversions raise provisional income, which can cause more Social Security benefits to become taxable - up to 85%. This "Social Security tax torpedo" can push effective marginal tax rates well above the headline tax bracket. An optimal Roth conversion plan considers at least three ceilings each year: the chosen top federal tax bracket, the target IRMAA threshold, and a provisional income range that avoids extremely high effective rates.

Revolutionary Wealth's tax planning process integrates these moving parts rather than treating IRMAA in isolation. And with the Tax Cuts and Jobs Act brackets - the tax cuts passed in 2017 - scheduled to sunset after 2025, future federal income tax brackets may rise. Converting at today's rates before that Jobs Act expiration could deliver substantial federal tax savings. That regulatory uncertainty makes proactive Roth conversion planning more urgent, not less.

IRMAA-aware conversion planning is not "fill up the 22% bracket and call it a day." It requires multi-year projections of MAGI, IRMAA brackets, RMDs, Social Security, and state taxes for both spouses over 20 to 30 years.

Revolutionary Wealth delivers independent advice and uses sophisticated retirement income and tax planning software similar to what large institutions use, but tailored to individual households. Our process gathers detailed account, income, and Social Security data; models several Roth conversion paths; weighs no-IRMAA, limited-IRMAA, and accept-IRMAA-for-a-few-years strategies; and stress-tests results against market returns and tax law changes. We use advanced planning technology to turn complexity into clarity.

Our core service areas supporting this work:

• Retirement Income Planning - coordinating Social Security, pensions, and withdrawal sequences

• Tax Planning - multi-year tax projection and bracket management

• Investment Management - managing taxable accounts and Roth account growth

• IRA/401(k) Planning - conversion sizing, RMD reduction, and Roth rescue strategies

The tax benefit of getting this right compounds every year. Stop guessing. Schedule a no-pressure conversation and see a personalized IRMAA-aware Roth conversion analysis for your situation.