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The Part B Premium and IRMAA in 2026

Most people who enroll in Medicare Part B pay the same standard monthly premium, which is set each year by the Centers for Medicare and Medicaid Services (CMS) and published at Medicare.gov. Higher earners pay more through a surcharge called the income-related monthly adjustment amount, or IRMAA. This guide explains how the base premium works, how IRMAA is layered on top, which year of income drives it, and it walks through example dollar figures so you can see the mechanism. Because the exact numbers change every year, treat every figure below as an illustration and confirm the current amounts at Medicare.gov and with the Social Security Administration (SSA) before you plan around them. To see your own enrollment dates, start with the enrollment window checker.

The standard premium is the starting point

Part B carries a monthly premium that most enrollees pay at the standard rate. CMS sets this figure annually and Medicare.gov posts it before the new year begins. If you collect Social Security, the premium is usually deducted straight from your monthly benefit, so you never write a check. If you are not yet drawing Social Security, Medicare bills you directly, typically every quarter. The standard premium is the same regardless of when in the year you enroll, though a late-enrollment penalty can be added permanently on top of it if you signed up late without protection.

What IRMAA is and how it stacks

IRMAA is not a separate bill. It is an amount added to your standard Part B premium when your income sits above a threshold that SSA sets. The higher your income, the higher the bracket, and the larger the monthly add-on. SSA also applies a parallel IRMAA surcharge to Part D drug coverage, so a high income can raise two premiums at once. The key point is that IRMAA is a cliff, not a gradual slope: cross a bracket boundary by a single dollar and you pay the full surcharge for that entire bracket.

Which year of income counts

Here is the detail that surprises people. SSA does not look at this year's income. It uses your modified adjusted gross income from your tax return two years earlier. For a 2026 premium, that generally means your 2024 tax return. That two-year lookback is why a one-time income spike, such as selling a house or a large retirement-account withdrawal, can raise your premium two years later even after your income has returned to normal.

If a major life event has since reduced your income, SSA lets you request a reconsideration. Events such as marriage, divorce, the death of a spouse, or stopping work can qualify you to have IRMAA recalculated on more recent figures. You make that request through SSA, not Medicare, so contact the Social Security Administration if your situation has changed.

Worked examples

Because the published brackets change yearly, the following uses clearly labeled example numbers to show the arithmetic, not the real 2026 amounts. Suppose the standard premium is $185 per month and the first IRMAA tier adds $75. A retiree whose 2024 income sat below the first threshold pays the full $185 and nothing more. A couple whose joint 2024 income crossed into the first IRMAA bracket would each pay $185 plus $75, or $260 per month apiece, which is $520 for the household. That is $900 more across the year for the two of them than the standard-premium couple, driven entirely by income from a tax return filed two years earlier.

Now picture a single filer whose 2024 income landed one dollar over the same threshold because of a large capital gain. Using the same example figures, that person pays $260 rather than $185, an extra $900 for the year, even though the gain was a one-time event. This is the cliff effect in action, and it is why some people time large withdrawals or Roth conversions with an eye on the bracket edges. Again, confirm the real thresholds and surcharge amounts at Medicare.gov, because the example dollars here are for illustration only.

Planning around the brackets

Two habits help. First, check the current brackets each fall when CMS publishes the new year's figures at Medicare.gov, and compare them against the tax return SSA will use. Second, if your income has dropped because of a qualifying life event, do not simply accept an IRMAA notice; ask SSA about a reconsideration. IRMAA is recalculated every year, so a surcharge you pay in one year can disappear the next once the high-income tax year rolls out of the two-year window.

How this connects to your enrollment timing

IRMAA does not change your enrollment deadlines, but it changes the cost of the coverage you enroll in, so it belongs in the same planning conversation. If you are still weighing when to take Part B, our guide on working past 65 and the Part B Special Enrollment Period covers when a delay is safe. And if you are simply trying to pin down your dates, run the enrollment window checker to see your Initial Enrollment Period at a glance.

A note before you rely on any figure

This article is general information, not medical, tax, or insurance advice. The premium and IRMAA numbers above are illustrative examples, not the official 2026 amounts. Confirm current premiums, brackets, and surcharge rules directly at Medicare.gov and with the Social Security Administration before making decisions, and speak with a tax advisor about how income timing affects your own brackets.