Retirement and Social Security
Definition
An extra charge added to Medicare Part B and Part D premiums for people with higher incomes, based on their tax return from two years earlier.
What it means
IRMAA stands for income-related monthly adjustment amount. Social Security uses the modified AGI on your federal tax return from two years earlier, so 2026 premiums are generally based on 2024 income. For 2026, the surcharges start when modified AGI is above $109,000 for single filers or above $218,000 for married couples filing jointly, and they rise in tiers. In the first tier, the total Part B premium is $284.10 instead of $202.90, and a Part D adjustment is added to the plan premium. If your income dropped because of a life-changing event, such as retirement, marriage, divorce or the death of a spouse, you can ask Social Security to use a more recent year with Form SSA-44. Large one-time income, such as a Roth conversion, can trigger IRMAA two years later.
Example
A single retiree whose 2024 modified AGI was $120,000 pays $284.10 a month for Part B in 2026, which is $81.20 more than the standard premium, or $974.40 more for the year.
Illustrative numbers only. Your situation will differ.