6 Medicare Premium Surcharges That Can Follow a High-Income Year

Medicare uses income from a prior tax year to determine whether higher-income beneficiaries owe IRMAA surcharges. In 2026, Part B IRMAA ranges from $81.20 to $487 per month, while Part D IRMAA ranges from $14.50 to $91 – Shutterstock

A high-income year can come with an unexpected Medicare sequel. Earn more today, and Medicare may use that income later to decide that future Part B and Part D premiums should cost more.

That system goes by a wonderfully bureaucratic name: the Income-Related Monthly Adjustment Amount, or IRMAA. The good news is that the rules make more sense once the numbers are separated from the alphabet soup, and the 2026 figures show exactly how much a high-income household can add to its monthly Medicare bill.