Tool · Medicare premium cliffs
IRMAA Trap Detector
See whether a Roth conversion, capital gain, RMD or other income event crosses a Medicare premium tier, which premium year feels it, and the one-year Part B and Part D change.
All calculations run locally in your browser. Your inputs are never transmitted or stored.
IRMAA in plain English
IRMAA is not a tax or fee on your Roth IRA. It stands for Income-Related Monthly Adjustment Amount: an extra monthly charge added to Medicare Part B (medical coverage) and Part D (prescription drug coverage) premiums when the income on the tax return Medicare uses is above a threshold.
Why it matters here: a Roth conversion moves money from a traditional IRA or pretax workplace account into a Roth IRA. The taxable portion generally counts as income that year. Medicare usually looks at the tax return from two years earlier, so a conversion can raise Medicare premiums two years later.
Added household IRMAA for the modeled premium year
Planning projection · not a published CMS table
MAGI before
MAGI after
Distance to next boundary
Measured before this event
Gross IRMAA after
Full modeled year, household
Part B and Part D breakdown
CMS assesses each enrolled person separately. Part D IRMAA is added to that person's plan premium.
| Coverage | Enrollees | Before / person / month | After / person / month | Added / household / year |
|---|---|---|---|---|
| Part B IRMAA | ||||
| Part D IRMAA |
Tier path
| MAGI band | Part B / month | Part D / month | Your scenario |
|---|---|---|---|
What this result means
SSA-44 boundary
Methodology & sources
One tax year, one later premium year
What the detector calculates
The core comparison is intentionally small and auditable:
IRMAA MAGI before = AGI + tax-exempt interest
IRMAA MAGI after = before + added AGI + added tax-exempt interest
annual IRMAA = 12 × [(Part B add-on × B enrollees) + (Part D add-on × D enrollees)]
A taxable Roth conversion increases AGI only by its taxable portion. If Form 8606 basis makes part of a conversion tax-free, do not enter the gross conversion as added AGI.
Published 2026 table versus a future projection
CMS published the 2026 table for 2026 premiums. SSA generally uses the 2024 return for that premium year. The published result is therefore 2024 MAGI → 2026 premiums.
A 2026 income event generally maps to 2028 premiums, but CMS has not published the 2028 thresholds or monthly adjustments. Future mode starts with the 2026 table and applies only the assumptions displayed above. Every such result remains labeled a projection.
The filing-status trap
Single, head of household, qualifying surviving spouse and MFS taxpayers who lived apart from the spouse for the entire tax year use the individual table. Married filing jointly uses the joint table.
MFS taxpayers who lived with the spouse at any time during the year use a separate schedule: in 2026, MAGI above $109,000 jumps directly to the level carrying $446.30 of Part B IRMAA and $83.30 of Part D IRMAA per person per month.
Can SSA lower IRMAA?
SSA may make a new determination after one of eight qualifying life-changing events: marriage; divorce or annulment; death of spouse; work stoppage; work reduction; involuntary loss of income-producing property; scheduled loss or reduction of employer pension income; or a qualifying employer settlement.
A Roth conversion itself is not a listed event. Retirement or work stoppage may qualify independently, but the newer actual or estimated MAGI still includes taxable conversion income for that year.
Important limits
- Uses the full Part B coverage table, not the separate immunosuppressive-drug-only table.
- Excludes late-enrollment penalties, Medicare Advantage premium reductions, Part D plan premiums and partial-year enrollment.
- Assumes the entered coverage counts apply for all 12 months.
- SSA can temporarily use three-year-old information when the usual return is unavailable and later correct the determination.
- This is an educational calculation, not an SSA determination or tax advice.
Primary sources
- CMS — 2026 Medicare Parts A & B Premiums and Deductibles
- SSA Handbook §2501 — IRMAA MAGI definition
- SSA Handbook §2504 — two-year lookback
- Form SSA-44 (12-2025) and 20 C.F.R. §418.1205
Last reviewed: August 22, 2026. Corrections: corrections@rothirahub.com.
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