IRMAA Brackets 2027: What Is Known, and What Is Not
The 2026 brackets (CMS — labeled 2026, for reference)
| MAGI — single | MAGI — married filing jointly | Total Part B premium | of which IRMAA | Part D surcharge |
|---|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 | — | — |
| Over $109,000 – $137,000 | Over $218,000 – $274,000 | $284.10 | $81.20 | $14.50 |
| Over $137,000 – $171,000 | Over $274,000 – $342,000 | $405.80 | $202.90 | $37.50 |
| Over $171,000 – $205,000 | Over $342,000 – $410,000 | $527.50 | $324.60 | $60.40 |
| Over $205,000 – under $500,000 | Over $410,000 – under $750,000 | $649.20 | $446.30 | $83.30 |
| $500,000 or more | $750,000 or more | $689.90 | $487.00 | $91.00 |
Married filing separately (lived with spouse): MAGI over $109,000 and under $391,000 falls in the $649.20 tier; $391,000 or more in the $689.90 tier. Amounts are per person — a couple with both spouses on Medicare pays two premiums. Source: CMS, "2026 Medicare Parts A & B Premiums and Deductibles" fact sheet (November 14, 2025). About 8% of Part B enrollees pay IRMAA.
The two-year lookback, and why the COLA matters to it
IRMAA tiers are set by modified adjusted gross income — your AGI plus tax-exempt interest — from the tax return of two years earlier: 2025 income sets 2027 premiums; 2027 income (the year of this COLA) will set 2029 premiums. Two consequences follow. First, nothing you do about 2027 income changes your 2027 premium — that ship sailed with your 2025 return. Second, the tiers are cliffs, not phases: one dollar of MAGI over a threshold puts the entire year's premium into the next tier. At the 2026 schedule, crossing the first threshold costs $81.20 a month — $974.40 a year, per person — which is why a one-off capital gain, a Roth conversion, or a pension start landing in a lookback year deserves planning. How the COLA itself feeds future MAGI is traced on COLA and your taxes.
What happens when CMS announces
On announcement day (expected November 2026, together with the standard premium and deductible): (1) the official 2027 brackets replace the 2026 reference table on this page; (2) the SSA applies the new tiers to your January 2027 premium, shown in your December COLA notice; (3) if your income has since dropped because of a life-changing event, Form SSA-44 is the route to a redetermination on more recent income. IRMAA payers should also know the protection asymmetry: the hold harmless rule does not apply to IRMAA tiers.
Frequently asked questions
What are the IRMAA brackets for 2027?
They have not been announced yet. CMS publishes the 2027 IRMAA brackets together with the standard Part B premium, expected in November 2026. Until then, the operative reference table is the 2026 brackets shown on this page — clearly labeled as 2026 — and any 2027 IRMAA figures elsewhere are estimates.
Which tax return sets my 2027 IRMAA?
Your 2025 return. IRMAA uses modified adjusted gross income (MAGI = adjusted gross income plus tax-exempt interest) from two years before the premium year — the 'two-year lookback'. A 2027 income change therefore cannot affect premiums until 2029.
How much is IRMAA in 2026?
On top of the $202.90 standard premium, the 2026 surcharges are $81.20, $202.90, $324.60, $446.30 and $487.00 a month across the five tiers, bringing the top total Part B premium to $689.90. Part D carries a parallel surcharge of $14.50 to $91.00 added to the plan premium.
Can I appeal an IRMAA determination?
Yes, if a life-changing event has reduced your income since the lookback year — marriage, divorce, death of a spouse, work stoppage or reduction, loss of income-producing property or pension, or an employer settlement. File Form SSA-44 with evidence and an estimate of the more recent year's MAGI.
Sources: CMS 2026 Medicare premiums fact sheet (brackets and amounts); SSA IRMAA rules (two-year lookback, Form SSA-44 life-changing events). 2027 brackets: pending CMS announcement.