IRMAA: the Medicare surcharge that looks back two years
By the RetireGlide Team · June 18, 2026
IRMAA (the Income-Related Monthly Adjustment Amount) is a surcharge added to Medicare Part B and Part D premiums for higher-income retirees — and it's determined by your modified adjusted gross income from two years earlier. For 2026, surcharges begin at roughly $109,000 of MAGI for single filers and $218,000 for joint filers (check medicare.gov for current figures).
IRMAA is a cliff system, not a phase-in: one dollar over a threshold triggers the full surcharge tier for both spouses for the entire year.
How the two-year lookback works
Your 2026 premiums are set by your 2024 tax return. That lag is why IRMAA ambushes new retirees: your last high-earning working years, a big Roth conversion, or a one-time capital gain can set surcharges for your first years on Medicare — even though your income has since fallen. Across the tiers, the combined Part B + Part D surcharge ranges from roughly $1,000 to over $6,000 per person per year.
What counts — and the moves that trigger it
IRMAA MAGI is AGI plus tax-exempt interest. The common tripwires are one-time income events that feel unrelated to Medicare:
- Roth conversions — the most frequent self-inflicted IRMAA event; a conversion at 63 shows up in premiums at 65.
- Large capital gains — selling a house beyond the exclusion, a business, or appreciated stock.
- RMDs — forced income that can push you over a tier every year once it starts.
- Even municipal bond interest — tax-exempt for income tax, but it counts for IRMAA.
Planning around the cliffs
Because tiers are cliffs, the marginal cost of the threshold dollar is enormous — which makes threshold-aware planning valuable: capping Roth conversions just below a tier, realizing gains in alternating years, or using QCDs to keep RMD income out of AGI. If your income genuinely dropped due to a life-changing event (retirement counts), file form SSA-44 to have the surcharge recalculated on your current income instead of the two-year-old return — many new retirees qualify and never file it.
A year-by-year projection that shows your distance to each IRMAA tier — including conversion scenarios — turns this from an annual ambush into a visible, manageable line item.
Frequently asked questions
- What income triggers IRMAA in 2026?
- Surcharges start at approximately $109,000 MAGI (single) / $218,000 (joint), based on your 2024 return. Thresholds adjust annually with inflation — verify current numbers at medicare.gov.
- Is IRMAA permanent?
- No — it's recalculated every year from the return two years back. A one-time income spike means one expensive year, not a permanent surcharge.
- Can I appeal IRMAA?
- Yes, if a life-changing event reduced your income: retirement, death of a spouse, divorce, and work stoppage all qualify. File form SSA-44 with evidence of the change — retiring is the most common successful appeal.
- Do Roth withdrawals count toward IRMAA?
- No. Qualified Roth withdrawals don't appear in MAGI, which is one reason retirees convert to Roth before Medicare age — pay the conversion tax early to keep income invisible to IRMAA later.
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Sources
RetireGlide is an educational modeling tool, not an investment, tax, or legal adviser. Numbers that change annually (tax thresholds, premiums, benefit formulas) are approximate — always verify against the official sources above. Read our full disclaimer.