What Is IRMAA?
The Income-Related Monthly Adjustment Amount is a surcharge on Medicare premiums for people above a certain income. Most people pay the standard Part B premium, which covers about a quarter of what the programme actually costs; the government pays the rest. IRMAA claws some of that subsidy back from higher earners, who pay 35, 50, 65, 80 or 85 percent of the cost instead of 25. It is not a separate bill — it is added to the premium already deducted from your Social Security payment, which is why many people discover it only when the payment shrinks.
Standard premium + the surcharge for your bracket = your monthly Part B premium
Why It's Based on Income From Two Years Ago
Because that is the most recent return the IRS has finished processing when premiums are set. Your 2026 premium is decided in late 2025, and the 2025 return has not been filed yet — so the 2024 return is the newest complete picture available. Social Security receives the figure from the IRS and applies it automatically.
The awkward consequence is that the year Medicare looks at is often the year you were still working, and the year you pay is the year you are not. Someone who retired in 2025 pays their 2026 premium on a full salary they no longer earn. That is exactly the situation the appeal process exists for, and it is covered below.
2026 Income Brackets
The standard premium is $202.90 a month. Above $109,000 of MAGI for a single filer, or $218,000 filing jointly, the premium steps up through five surcharged brackets to $689.90. The joint thresholds are double the single ones all the way up, except at the top, where $500,000 becomes $750,000 rather than a million — a marriage penalty that only bites the highest bracket.
Two details of the brackets catch people out. The first is that they are cliffs, not slopes: one dollar over a threshold moves the whole premium up a tier, so a dollar of extra income can cost $974 over the year. The second is what happens to a married couple who file separately and lived together at any point in the year — the middle brackets vanish and the premium jumps straight from $202.90 to $649.20 above $109,000. Filing separately while on Medicare is worth checking with a tax preparer first.
What If My Income Has Dropped? (Appeals)
You can ask Social Security to use a more recent year instead, using Form SSA-44. It is not a general appeal — it works only where a specific life-changing event caused the drop:
- Retirement, or any other stopping or reduction of work. This is the most common one by far.
- Marriage, divorce or annulment, or the death of a spouse.
- Loss of income-producing property through a disaster, fraud or theft — not through a sale or a bad investment.
- Loss or reduction of a pension, or a settlement from a former employer's closure or bankruptcy.
Send the form with proof — a letter from an employer, a death certificate, a divorce decree — to your local Social Security office. It is worth doing promptly: the surcharge keeps coming out of every payment until the decision is made, and a year in the wrong bracket can cost thousands.
Important Disclaimer
This is an educational estimate of your 2026 Medicare Part B premium only (Part D IRMAA is not included, since it depends on your specific drug plan). IRMAA is based on your MAGI from two years prior. This tool uses a cliff structure — exceeding a threshold by even $1 moves you into the next tier. If your income has dropped since the year used for this calculation (e.g., due to retirement, marriage, divorce, or death of a spouse), you may be able to appeal using SSA Form SSA-44. For an official determination, contact the Social Security Administration. ssa.gov