What is IRMAA and will it raise my Medicare premiums?

IRMAA stands for income-related monthly adjustment amount. Social Security uses your modified adjusted gross income, which is adjusted gross income plus tax-exempt interest, to decide whether you pay more than the standard Part B premium and an extra amount on Part D.

For 2026 the Part B tiers for single filers are: up to $109,000 pays the standard $202.90; above $109,000 to $137,000 pays $284.10; above $137,000 to $171,000 pays $405.80; above $171,000 to $205,000 pays $527.50; above $205,000 and under $500,000 pays $649.20; $500,000 or more pays $689.90. Joint filer thresholds are double up to the $410,000 tier, and the top joint tier starts at $750,000. Part D adds $14.50 to $91.00 a month on top of the plan premium.

It looks back two years. For 2026 premiums, Social Security generally uses the tax return filed in 2025 for tax year 2024. So a large Roth conversion, home sale gain or final-year bonus at 63 can show up as higher premiums at 65.

Worked example: a single filer with $120,000 of 2024 income pays $81.20 more for Part B and $14.50 more for Part D each month in 2026. That is $95.70 x 12 = $1,148.40 for the year. The tiers are cliffs: one dollar over a threshold puts you in the higher tier.

If your income has dropped because of a life-changing event, such as stopping work, reduced hours, marriage, divorce, a spouse's death, or loss of a pension, you can ask for a new decision with form SSA-44 using more recent income. You can also appeal the decision itself.