Medicare costs, and where each figure comes from

What IRMAA is and how it works covers the two-year lookback, how the tiers step, what counts as income, how a determination arrives, and when SSA will use a later tax year.

IRMAA brackets for 2026 is the full table: every threshold, the Part B and Part D surcharge for each tier, and the CMS document each figure came from. Earlier years are at 2025, 2024, 2023, and how the figures are calculated shows the derivation CMS publishes and the one it does not.

At the other end of the income range, the Medicare Savings Programs pay the Part B premium — QMB pays the deductibles and coinsurance too, while SLMB and QI cover the premium at higher income bands. The federal limits are a floor: of the 51 states checked so far, 12 apply no asset test at all.

Separately from income, signing up late adds a permanent surcharge. The Part D late enrollment penalty is 1% of a CMS figure for every uncovered month, and Form CMS-L564 is what proves employer coverage and avoids the Part B version. Both are separate from IRMAA, and one person can pay both.

Every figure here is the amount CMS published, not one re-derived from the statutory percentages — those differ by a few cents, and we show why. Thresholds come from SSA POMS HI 01101.020. Years CMS has not published carry no table.

We do not sell insurance, take commissions, or hand your details to an agent, and no tool here asks for your email. See every source we use or who publishes this.