On a joint return the couple has one modified adjusted gross income, and Social Security uses it for both spouses. The calculator opens with a joint MAGI of $230,000 from the 2025 return and both of you on Medicare: that is $12,000 over the first joint edge, so each spouse pays tier 1, and the household figure doubles it.
How to read it for a couple
- The tier is the same for both of you. The monthly Part B premium and the Part D surcharge shown are per person.
- The household line (Both spouses, surcharge a year) adds them up when both are enrolled. Untick Both spouses are on Medicare if one of you is still on employer coverage or not yet 65; only the enrolled spouse pays.
- The cliff line is in household terms too: one dollar over a joint edge costs both of you a full tier.
What makes joint brackets different
Up to tier 4 the joint edges are exactly twice the individual ones ($218,000 against $109,000 for the first, in 2026). The top tier is the exception: it starts at $750,000 joint against $500,000 individual, so tier 4 is much wider for couples. Married couples who file separately and lived together don’t get half the joint brackets; they get a separate table that starts tier 4 straight after $109,000.
Years of change
The year one spouse retires, or the year after a spouse dies, the income on the return two years back can be much higher than what you live on now. Both are life-changing events Social Security accepts on Form SSA-44; it asks for documents showing what happened and how much the income fell. A widow or widower also moves from the joint to the single brackets once a single return is used, and those brackets are half as wide, so a survivor’s IRMAA can rise even when the household income falls.
2027 joint brackets: one spouse and both
| Tier | Joint MAGI (2025 return) | Part B a month, each | Part D IRMAA, each | Surcharge a year, one spouse | Surcharge a year, both |
|---|---|---|---|---|---|
| Standard | $218,000 or less | $202.90 | $0.00 | $0.00 | $0.00 |
| Tier 1 | $218,001 – $274,000 | $284.10 | $14.50 | $1,148.40 | $2,296.80 |
| Tier 2 | $274,001 – $342,000 | $405.80 | $37.50 | $2,884.80 | $5,769.60 |
| Tier 3 | $342,001 – $410,000 | $527.50 | $60.40 | $4,620.00 | $9,240.00 |
| Tier 4 | $410,001 – $749,999 | $649.20 | $83.30 | $6,355.20 | $12,710.40 |
| Tier 5 | $750,000 or more | $689.90 | $91.00 | $6,936.00 | $13,872.00 |
Provisional: CMS hadn't published 2027 figures as of October 18, 2026, so these are the official 2026 figures. With drug coverage for each spouse. Sources: CMS, 2026 Medicare Parts A & B Premiums and Deductibles; SSA, Premiums: Rules for Higher-Income Beneficiaries; SSA, Request to lower IRMAA.