IRMAA, the Income-Related Monthly Adjustment Amount, is a surcharge added to your Part B and Part D premiums when your income is above a threshold. For 2026, it starts at $109,000 for a single filer and $218,000 for a joint return. Social Security uses your tax return from two years ago, so your 2026 premium is based on your 2024 income. If your income has dropped since then because of retirement or another life change, you can appeal and have it reduced.
The 2026 brackets
Below $109,000 single or $218,000 joint, you pay the standard Part B premium of $202.90.
Above that, the surcharge rises in five steps. The first step adds about $81 a month to Part B and about $14 to Part D. The top step, above $500,000 single or $750,000 joint, brings Part B to roughly $689 a month. The surcharge applies per person, so a couple pays it twice.
Income here means modified adjusted gross income: your adjusted gross income plus tax-exempt interest. One dollar over a line puts you in the next bracket for the whole year.
Why the two-year lag catches retirees
The year you retire, Social Security looks at a return from when you were still earning a full salary. Many people get an IRMAA letter in their first year of Medicare that has nothing to do with their current income.
Appealing with a life-changing event
Social Security lists specific events that let you ask for a recalculation using your current income: you stopped working or reduced hours, you married, divorced or were widowed, you lost income-producing property, your pension ended or was cut, or you received an employer settlement. Retirement is the common one.
File form SSA-44 with proof, such as a retirement letter from your employer, and an estimate of this year's income. Approval replaces the two-year-old figure with your current one.
A one-time spike, such as selling a house or converting an IRA to a Roth, does not qualify. The surcharge lasts one year and drops off when the later return shows normal income.
Planning around it
If you are within a few thousand dollars of a bracket, timing a withdrawal, a Roth conversion or a capital gain into a different year can avoid a full year of surcharges. That is a conversation for your tax adviser, and I am happy to explain the brackets to them.
Got an IRMAA letter that does not match your life? Request a plan check and bring the letter. Filing the appeal is part of what I do.