IRMAA Check

IRMAA Two-Year Lookback

Quick answer: Your 2026 IRMAA is generally based on your 2024 tax return, because Medicare usually uses a two-year lookback for premium surcharges.

The income you report this year can affect Medicare premiums two years later, which is why IRMAA planning often starts before Medicare begins.

Estimate your future surcharge
Older adult organizing Medicare and Social Security paperwork for a premium review

Short answer: For 2026 premiums, Medicare generally reviews 2024 Medicare MAGI. A large income event today can appear in your Medicare costs later.

Before the tax year closes

If this year may be used for a future Medicare premium year, run the estimate while you can still adjust the income decision.

Estimate the future surchargeTest MAGI, Roth conversions, RMDs, and gains. Save the planning checklistUse it before year-end income decisions.

Which tax return does Medicare use for IRMAA?

Social Security generally starts with tax-return information from two years before the Medicare premium year. The premium amounts and income brackets can change annually, but the usual lookback timing follows this pattern:

Medicare premium yearIncome year generally usedStatus
20252023 incomeOfficial premium year
20262024 incomeOfficial premium year
20272025 incomeExpected lookback year; official 2027 surcharge amounts are not yet published

Important: Do not use estimated 2027 brackets as if they were official. As of June 7, 2026, CMS has not published the official 2027 Medicare Part B and IRMAA amounts.

How income at age 63 can reach your Medicare premium at age 65
Age 63Income yearRoth conversions, gains, withdrawals, and other MAGI events happen here.
Age 64Planning yearReview the tax return, expected Medicare start, and any qualifying life changes.
Age 65Premium yearSocial Security generally uses the return from two years earlier for IRMAA.

Why age 63 matters

If Medicare starts at age 65, the tax year when you are age 63 may be the first year used for your first Medicare IRMAA decision. That does not mean every person must avoid income at age 63. It means Roth conversions, RMD planning, capital gains, and home sales deserve a quick IRMAA check before the year closes.

What income gets reviewed?

IRMAA uses Medicare MAGI. For most planning conversations, that means adjusted gross income plus tax-exempt interest. Taxable IRA withdrawals, Roth conversions, capital gains, pensions, and taxable Social Security can all matter.

Review what counts in Medicare MAGI

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Education sponsor placement for annual IRMAA threshold updates or retirement income planning resources.

Simple lookback checklist

  • Estimate this year's Medicare MAGI before making a large income move.
  • Compare the estimate with the IRMAA brackets for the Medicare premium year you are planning around.
  • Remember that a one-year spike usually affects only one premium year unless income remains high.
  • Do not assume SSA-44 applies just because the income was unusual.

Get the two-year lookback checklist

Receive practical reminders about premium-year timing, annual bracket updates, and Medicare MAGI items to review before the tax year closes.

Two-year lookback questions

What tax year does Medicare use for IRMAA?

Medicare generally uses tax-return information from two years before the premium year. For 2026 Medicare premiums, that usually means 2024 Medicare MAGI. If the most recent return is unavailable or your circumstances changed, Social Security may use different information.

Does IRMAA change every year?

Yes. Social Security reviews IRMAA annually. A one-year income spike usually affects one Medicare premium year unless your income remains above a threshold or another large income event follows it.

Why do people talk about age 63 for IRMAA?

For someone starting Medicare at age 65, the tax return from age 63 may be used for the first IRMAA determination. Age 63 is a planning checkpoint, not a rule that everyone must avoid income.

What income year will 2027 IRMAA use?

Under the usual two-year lookback, 2027 IRMAA will generally use 2025 income. The 2027 surcharge amounts have not been officially published as of June 7, 2026, so avoid treating projected brackets as final.

Official source notes

Medicare.gov states that the Part B premium can be higher depending on income. Social Security handles requests to lower IRMAA when a qualifying life-changing event reduces household income.

Read the SSA Handbook section on higher Medicare premiums and the CMS 2026 Medicare premium fact sheet for official guidance.

Next step: run a surcharge estimate and save the IRMAA planning checklist.