The answer
What is IRMAA for Medicare?
IRMAA stands for Income-Related Monthly Adjustment Amount, an extra charge some people pay on top of their standard Medicare premiums.
It applies to Part B (doctor and outpatient coverage) and Part D (prescription drug coverage) when your reported income is above a set threshold. In 2026, IRMAA begins for single filers with income above $109,000 and for joint filers with income above $218,000. The amount added increases at higher income levels. IRMAA is based on your tax return from a prior year, so a higher-income year can affect your premiums later on. If your income has dropped due to a major life change, you can ask Social Security to reconsider. In short, IRMAA means higher earners pay more for the same coverage.