IRMAA means income-related monthly adjustment amount. It is an extra charge added to certain Medicare premiums when income is above set levels.
What it means
IRMAA stands for income-related monthly adjustment amount. It can raise the price of Medicare Part B and Part D.
Medicare generally looks at tax-return income from two years earlier. That delay is why a large gain, Roth conversion, or retirement payout can show up in a later Medicare bill.
A simple example
Income reported on a 2026 tax return may help set a 2028 Medicare charge. A large Roth conversion, investment gain, or retirement payout in 2026 could make the 2028 Part B and Part D premiums higher, even if your income has fallen by then.
Suppose the extra income came from one unusual event or you stopped working after that tax return. You can ask Social Security whether the reason qualifies for a new decision. The request may or may not be approved, but knowing which old tax return caused the charge tells you what to review.
What people often miss
IRMAA uses income steps. Going just over a line can move the premium to the next step.
You may be able to ask for a new decision after certain life-changing events, such as stopping work. A request is not automatic approval.
Three questions worth asking
- Which tax year is Medicare using?
- Was the higher income a one-time event?
- Does a life-changing event let me ask Social Security to review the amount?
Checked against primary sources
This explanation was checked against the sources below. Rules and limits can change, so check the source before making a decision.
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