Roth Conversion + Medicare IRMAA 2027 Tradeoff Calculator
Calculate if a Roth conversion crosses 2027 IRMAA tiers and raises your Medicare Part B/D premiums two years later. See the true after-IRMAA cost of the conversion. Free, private.
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What is IRMAA and why does it matter for Roth conversions?
IRMAA (Income-Related Monthly Adjustment Amount) is a Medicare premium surcharge added to your standard Part B and Part D premiums when your modified adjusted gross income (MAGI) exceeds set thresholds. The base 2027 Part B premium is approximately $194/month; IRMAA surcharges add $73-$456/month on top, depending on the tier you reach. IRMAA uses the tax return from 2 years prior — so your 2027 income determines your 2029 Medicare premiums.
A Roth conversion is fully taxable as ordinary income in the conversion year. That income increases your MAGI. If the conversion pushes MAGI across an IRMAA threshold, you'll pay higher Medicare premiums for the full year, 2 years later. The IRMAA "cliff" is harsh — $1 over the threshold triggers the full tier surcharge ($876+/year per person for tier 1, climbing to $5,500+/year per person for tier 5).
2027 IRMAA tiers (single filer, MFJ doubled)
Single filer thresholds for 2027 (estimated, inflation-adjusted):
- Tier 0: MAGI under $109,000 — base premium only
- Tier 1: $109,001-$137,000 — +$73/mo Part B + $14/mo Part D = ~$1,044/yr
- Tier 2: $137,001-$170,000 — +$184/mo Part B + $36/mo Part D = ~$2,640/yr
- Tier 3: $170,001-$203,000 — +$295/mo Part B + $59/mo Part D = ~$4,248/yr
- Tier 4: $203,001-$500,000 — +$406/mo Part B + $81/mo Part D = ~$5,844/yr
- Tier 5: $500,001+ — +$456/mo Part B + $87/mo Part D = ~$6,516/yr
MFJ thresholds are roughly double, but the surcharge per person is the same. A married couple both on Medicare in tier 2 pays $2,640 × 2 = $5,280/year extra.
Strategies to convert without triggering IRMAA
Convert below the cliff. If your base MAGI is $130,000 and the tier 2 threshold is $137,000, you can convert up to $7,000 without crossing the cliff. Use this calculator to find the exact "room" available.
Convert before age 63. IRMAA uses returns from 2 years prior. If you convert in the year you turn 63 (when Medicare starts at 65), the income shows up on the 65-year-old return that determines 67 IRMAA. By spreading large conversions before age 63, you avoid the Medicare premium cascade entirely.
Spread across years. Instead of one $200,000 conversion at age 67 (triggering tier 4), do five $40,000 conversions at age 63-67 — keeping each year just below the IRMAA cliff that matters.
SSA-44 life-changing event. If you converted in a peak earnings year and then retired, file Form SSA-44 to ask Medicare to use your current (lower) income for IRMAA. Approval requires a qualifying life event: work stoppage, work reduction, marriage, divorce, death of spouse, or loss of pension.
How to use this calculator
Enter your base MAGI for the conversion year (all other income — pension, Social Security, dividends, RMDs — before adding the Roth conversion). Enter the planned Roth conversion amount. Pick your filing status, whether one or both spouses are on Medicare, your federal marginal bracket, and state tax rate.
The calculator returns: (1) total income tax on the conversion (fed + state), (2) annual IRMAA surcharge in 2029 from this conversion, (3) which IRMAA tier you'd land in, and (4) total all-in cost. Compare the all-in cost vs the tax saved on future RMDs — only convert if the math works after IRMAA. The "room available" hint shows how much you can convert and still stay in your current tier.
Source: SSA.gov (Medicare IRMAA brackets), CMS.gov (Part B/D premiums), IRS Pub 590-A (Roth conversion rules) — updated May 2026.