Why your Medicare premium
might be higher than $202.90.

IRMAA guide

The Medicare premium quote that surprises people.

Most people expect to pay the standard $202.90/month Part B premium in 2026 — and most do. But if your income was above $109,000 (single) or $218,000 (married filing jointly) two years ago, Medicare adds a surcharge called IRMAA on top of both your Part B and Part D premiums. It isn't hidden or unusual — it's a standard part of how Medicare funds itself — but it catches people off guard almost every year, usually because of the two-year lookback.

The 2-year lookback

Your 2026 Medicare premium is set using your 2024 tax return — not your current income. This is simply how the timing works: your current year's tax return isn't filed yet when premiums need to be calculated, so Medicare uses the most recent complete return on file with the IRS. That means a retiree whose income has since dropped can still be paying IRMAA based on their old salary — which is exactly the gap the appeal process below exists to fix.

Five tiers, and a cliff at each one

IRMAA has five income tiers above the standard rate (three for Married Filing Separately, which has a much steeper structure). The critical thing to understand is that each tier is a cliff, not a phase-in: crossing a threshold by even a single dollar triggers that entire tier's surcharge, not a prorated amount. Someone at $109,001 MAGI (single) pays the exact same Part B surcharge as someone at $136,999 — both land in the same bracket. This calculator flags it explicitly when your MAGI is within $1,000 of the next threshold, since a small, avoidable difference in MAGI can mean a real jump in premium.

What counts as MAGI (the muni-bond surprise)

For IRMAA specifically, MAGI means your Adjusted Gross Income plus tax-exempt interest — most commonly interest from municipal bonds. Muni bond income is genuinely free of federal income tax, which leads people to assume it's invisible to Medicare too. It isn't: it gets added back in specifically for this calculation, so a portfolio that's tax-efficient for income tax purposes can still push someone into a higher IRMAA bracket.

A worked example

A single filer with a 2024 MAGI of $150,000 falls into the second IRMAA tier ($137,001–$171,000): their Part B premium is $405.80/month instead of the standard $202.90, plus a $37.50/month Part D surcharge — $443.30/month combined, or $2,884.80 more per year in surcharges than someone just under the first threshold. If that same person's MAGI had been $170,900 instead — $100 short of the next tier — they'd still be in this same bracket; only crossing $171,000 itself would push them to the next one.

Appealing with Form SSA-44

If your income has genuinely dropped since the 2-year-old tax return Medicare is using — because of retirement, marriage, divorce, the death of a spouse, or a reduction in work hours — you don't have to just accept the higher premium until the lookback catches up. Form SSA-44 lets you ask Social Security to base your IRMAA on your current, lower income instead, and if approved, it can come with a retroactive refund for months you were overcharged. This is genuinely underused: many retirees keep paying a working-years IRMAA rate for a year or more simply because they didn't know the form existed.

Disclaimer

This calculator uses the 2026 IRMAA brackets published by CMS for illustrative purposes and does not account for every possible individual circumstance. Brackets are adjusted annually and CMS is the authoritative source — always verify your specific situation at ssa.gov or medicare.gov, or with a licensed advisor, before making coverage decisions.