The five years after · Retirement Transition Trap™
Medicare and income-related surcharges
A surcharge assessed on a tax return you filed in a prior year.
In short
Medicare premiums are not flat. Above certain income levels an income-related monthly adjustment amount applies, and it is assessed on a tax return from a prior year, so a single high-income year can raise premiums after the fact.
How it works
Above certain income levels, Medicare costs more, through an income-related monthly adjustment amount applied on top of the standard premium.
The mechanism that surprises people is the lookback: the surcharge is assessed using a tax return from a prior year, not the current one. A decision made in one year can raise premiums in a later one, after the money has already been spent.
Why it belongs in the transition window
The window is full of one-off income events: a Roth conversion, a property sale, a pension lump sum, a final bonus, a large distribution to fund something. Each can lift income in a single year.
A one-year spike does not just cost tax in that year. If it crosses a surcharge threshold it also raises premiums in the year the lookback lands on. That is a second cost, and it is the one people do not price in.
The brackets change, so this page does not list them
The income levels at which surcharges begin, and the amounts, are set annually. Quoting them here would make this page wrong within a year.
What is durable is the shape of the thing: there are thresholds, crossing one has a cost, and the assessment looks backwards. That is enough to know it needs checking before a large one-off income event, not after.
This page explains a mechanism. It is not investment, tax or legal advice, and it deliberately quotes no thresholds, ages or rates. Those are set annually, and a page that named them would be out of date within a year.
Check where you stand
Ten questions, about two minutes
The readiness checklist covers this and nine other checkpoints, and tells you which you have already handled. No contact details required.
Where does this sit in your plan?
Fifteen minutes on the phone about your own situation, which is the part this page can’t tell you.