Circle It in Red · Social Security & Medicare mechanics
The Cliff Two Years Back: how a good year raises your Medicare premium
A note on who Max is. Max is a cartoon owl. He is not a financial advisor, insurance agent, or tax professional, and nothing here is personalized advice. When a question turns personal, he does not answer it — he teaches the general version and points you to a licensed conversation, which is automated and says so before it says anything else.
A woman in Boca Raton sold the house she raised three kids in, took the gain, and felt fine about it. Two years later her Medicare premium went up, and she had no idea why. Nothing about her had changed. The tax year that decided it was already over.
The mechanism
Most people pay the standard Medicare Part B premium and never think about it again.
But above a certain income, Medicare adds a surcharge on top of that standard premium — and a matching one on top of your Part D drug coverage. The surcharge is called IRMAA: the income-related monthly adjustment amount. Two things about it surprise people.
First, the income it looks at is your modified adjusted gross income from two years ago. The premium you pay in 2026 was decided by the return you filed for 2024. By the time you feel it, the year that caused it is closed.
Second, it is a cliff, not a ramp. Cross the income line by a single dollar and the whole higher amount applies for the entire year. There is no easing into it. One dollar over the edge is the same fall as a thousand.
The 2026 income lines and the exact surcharge amounts were not yet confirmed when this was written, so I am not going to print a number I would have to take back. What matters is the shape: a step, set two years in arrears. You can plan around a step you can see.
Who trips it, and who does not
At risk
- Anyone with a one-time income spike two years before a Medicare year: a home sale, a large capital gain, a big Roth conversion, an inherited IRA distribution.
- Couples where one spouse's death changes the filing status that the income line is measured against.
Less of a worry
- Steady, modest retirement income well below the first line.
- Income made mostly of Roth withdrawals and return of basis, which do not land in the measure.
Let me circle the part that bites.
The premium is set by a year you have already lived.
This is the trap in a conversion year. You fill a low bracket with a Roth conversion, you do everything right on the income-tax side — and two years later the same income nudges you over an IRMAA step and quietly raises your Medicare premium for twelve months. The conversion still may have been worth it. But if nobody counted the step, it is a surprise instead of a decision.
The one thing to know: a genuine life-changing event — retirement, a spouse's death, marriage, divorce, loss of a pension — can be appealed with Social Security form SSA-44, which asks them to use a more recent, lower year. The appeal is free and it is education, not a product. Nobody has to sell you anything to file it.
Figures on this page are for tax year 2026 and were last verified 2026-07-25. Tax and benefit numbers change every year — check the current-year figure before acting on any of them. The 2026 Medicare IRMAA income tiers were not yet confirmed when this was written; where they matter, they are named but not stated as fact.
If your question is “how much will mine be?”
Wrong question — the tiers for your year are the current-year figure, and they change. Better question: is a big income event landing two years before a Medicare year, and have I counted the step? That is arithmetic anyone can do once they know the step is there. The part that needs your actual return is a licensed conversation, and it is not mine.
Traps and topics named in this piece
Max out. Roth well.
Desk’s open.
— Max