Medicare IRMAA Brackets Explained

Why does a single extra dollar of income sometimes cost you more than a thousand dollars in Medicare premiums? Because IRMAA, the Income-Related Monthly Adjustment Amount, isn’t a gradual tax. It’s a set of cliffs. Step one dollar over a line and the full surcharge for that tier lands on you, every month, for the whole year.

How it actually works

IRMAA is a surcharge that rides on top of your standard Medicare Part B and Part D premiums once your income clears certain thresholds. For 2026, the standard Part B premium is $202.90 a month. If you stay under the first line, that’s what you pay. Above it, the surcharge stacks on fast.

Here’s the part that catches people. Your 2026 surcharge is based on your 2024 tax return. Medicare uses a two-year lookback, the modified adjusted gross income (MAGI) from your return two years prior. So the income decision that triggers a surcharge already happened. You’re paying today for a choice you made before you were even on Medicare.

The 2026 brackets

For 2026, here’s what a married couple filing jointly pays for Part B per person, by 2024 MAGI:

2024 MAGI (married filing jointly)	Total monthly Part B premium
≤ $218,000	$202.90
> $218,000 to ≤ $274,000	$284.10
> $274,000 to ≤ $342,000	$405.80
> $342,000 to ≤ $410,000	$527.50
> $410,000 to < $750,000	$649.20
≥ $750,000	$689.90

Single filers hit the same surcharges at exactly half those income lines. And Part D carries its own surcharge on top, from $14.50 a month at the first tier up to $91.00 at the top. Cross from the standard tier to the top one and you’ve taken a couple from $202.90 to $689.90 a month each, just on Part B. For two people, that’s the better part of $12,000 a year in surcharges alone.

The cliff is the whole story

A normal tax bracket only taxes the dollars above the line. IRMAA taxes you as if every dollar counts the moment you cross. Go one dollar over $218,000 as a couple and your premium jumps about $81 a month each, $1,946 a year for the two of you, for a single dollar of income.

That changes how you think about year-end moves. A Roth conversion, a big capital gain, a large RMD, selling a rental, even an unusually good year of dividends. Any of them can push you over a line you didn’t know was there, and the bill shows up two years later when you’ve forgotten the cause.

If your income is lumpy or large

This is where it pays to plan two years ahead instead of reacting. If you’re doing Roth conversions, size them to fill a tier, not blow through it. The goal isn’t to avoid IRMAA at all costs. Sometimes paying one tier of surcharge to convert at a low rate is the right trade. The mistake is tripping a cliff by accident.

Two more things worth knowing. A Qualified Charitable Distribution sends RMD money straight to charity and keeps it out of MAGI entirely, which can hold you under a line. And if your income drops because of a life-changing event like retirement or a spouse’s death, you can file Form SSA-44 and ask Medicare to use your current income instead of the two-year-old number. Most people never file it.

IRMAA rewards the people who saw the cliff coming. The income that triggers your premium is sitting on a tax return you can already read. Read it.