IRMAA Two-Year Lookback: Which Tax Year Counts
Last updated · Sources: CMS, SSA, BLS
SSA determines IRMAA using the IRS-provided MAGI from the tax year two years before the premium year (20 CFR 418.1135). If that return is not available, SSA can use the return from three years before and correct it once the newer one arrives.
| Premium year | Tax year (MAGI) used | Thresholds |
|---|---|---|
| 2026 | 2024 | Official: > $109,000 / $218,000 |
| 2027 | 2025 | Projected > $112,000 / $224,000 |
| 2028 | 2026 | Not yet determinable (depends on CPI-U through August 2027) |
Why it matters for planning
Because of the lag, income decisions you make in a given year — Roth conversions, capital gains, a large IRA withdrawal — show up in your Medicare premiums two years later. Someone turning 65 in 2027 will have 2027 premiums set by their 2025 income, often a full working year.
If that older year overstates your current income because of a life-changing event, see how to appeal IRMAA with Form SSA-44. Planning a conversion? Read Roth conversions and IRMAA.
Questions
What tax year is used for 2027 IRMAA?
Your 2025 tax return (filed in 2026). If SSA does not have it from the IRS, it may use your 2024 return and adjust later.
I retired and my income fell. Do I still pay IRMAA?
SSA uses the older return by default. If the drop was due to a qualifying life-changing event such as work stoppage, you can ask SSA to use a more recent year with Form SSA-44.