Which year's income does 2026 Medicare IRMAA use?

Generally MAGI from your 2024 return, meaning AGI plus tax-exempt interest. SSA gets the data from the IRS; if the latest return isn't available, it uses the one from three years back and adjusts later. 2027 premiums will use 2025 income.

At what income does IRMAA start in 2026?

Above $109,000 of MAGI for a single filer or $218,000 for a joint return. Part B rises from the standard $202.90 to between $284.10 and $689.90 per person per month, and Part D adds $14.50 to $91.00. One dollar over a threshold puts you in the full tier.

My income dropped when I retired. Can I pay less IRMAA?

You can ask. Retirement is a work stoppage, one of the events Form SSA-44 accepts. Attach proof from your employer and your current-year estimate (or a filed return) and ask SSA to use the new income. Approval depends on your documents, and SSA adjusts later if the estimate was low.

A Roth conversion pushed me into IRMAA. Can I use SSA-44?

Generally no. One-time income such as a Roth conversion or a home or stock sale isn't one of the eight life-changing events. The fix is planning ahead: convert before 63, or spread conversions over several years and keep each year under a threshold.

Does tax-free municipal bond interest affect IRMAA?

Yes. IRMAA MAGI is AGI plus the tax-exempt interest on line 2a of Form 1040, so municipal bond interest counts even though it isn't federally taxed. Foreign earned income excluded under the FEIE is added back too.

Medicare IRMAA 2026 Brackets and SSA-44

Your 2026 Medicare premiums are based on your 2024 tax return. If modified adjusted gross income (MAGI, which is AGI plus tax-exempt interest) was above $109,000 for a single filer or $218,000 for a joint return, you pay an income-related monthly adjustment amount (IRMAA) on both Part B and Part D. After retirement, divorce, a spouse's death or another of eight life-changing events, Form SSA-44 asks SSA to use a more recent year's income; a one-time spike in income isn't a reason on its own.

What are the 2026 IRMAA brackets?

These are the 2026 figures CMS released on November 14, 2025, per person per month. If both spouses are on Medicare, each pays.

No surcharge: single $109,000 or less, joint $218,000 or less. Part B is the standard $202.90 and Part D has no add-on.

Tier 1: single $109,001 to $137,000, joint $218,001 to $274,000. Part B $284.10, plus $14.50 for Part D.

Tier 2: single $137,001 to $171,000, joint $274,001 to $342,000. Part B $405.80, plus $37.50 for Part D.

Tier 3: single $171,001 to $205,000, joint $342,001 to $410,000. Part B $527.50, plus $60.40 for Part D.

Tier 4: single $205,001 to $499,999, joint $410,001 to $749,999. Part B $649.20, plus $83.30 for Part D.

Tier 5: single $500,000 or more, joint $750,000 or more. Part B $689.90, plus $91.00 for Part D.

Married filing separately and living with your spouse: above $109,000 and under $391,000 you go straight to $649.20 for Part B and $83.30 for Part D, and $391,000 or more puts you in the top tier. Filing separately is costly for IRMAA.

The Part D surcharge is on top of your plan's premium and is paid to Medicare, not the insurer. If you're on Social Security, it's deducted from your benefit.

How is MAGI figured, and what gets added back?

Under SSA's operations manual (POMS HI 01101.010), IRMAA MAGI is AGI from line 11 of Form 1040 plus tax-exempt interest from line 2a. In other words, municipal bond interest is free of federal income tax but still counts for IRMAA. Under Section 1839(i) of the Social Security Act, foreign earned income excluded under the FEIE is added back too.

What stays out of MAGI: qualified Roth IRA distributions, HSA distributions used for medical costs, and the untaxed part of Social Security. The OBBBA's extra $6,000 deduction for people 65 and older is taken after AGI, so it lowers income tax but not IRMAA.

The two-year look-back: your income at 63 sets your premium at 65

SSA gets return data from the IRS and generally uses the return from two years before the premium year: 2026 uses 2024, and 2027 uses 2025. If the latest return isn't available, SSA starts with the one from three years back and adjusts later.

So a Roth conversion, home sale, business sale or big bonus at 63 shows up in your Medicare premiums two years later. Each tier is also a cliff: one dollar over a threshold and you pay that tier's full amount for the year.

Which events qualify for Form SSA-44?

SSA accepts eight life-changing events (POMS HI 01120.001):

Work stoppage, meaning retirement; work reduction, such as going part-time or cutting hours; marriage; divorce or annulment; and death of a spouse.

Loss of income-producing property, but only for reasons beyond your control, such as a natural disaster, arson or criminal theft (POMS HI 01120.035). Selling or giving property away, or ordinary investment losses, don't count.

Loss of employer pension income, for example because the employer went bankrupt or the plan was terminated or cut, and an employer settlement payment, such as money received because of an employer's bankruptcy or reorganization.

The event has to cause a significant drop in MAGI, or a change in filing status that moves you to a table with lower thresholds.

How do you file it, and what do you attach?

After SSA sends your IRMAA determination, complete SSA-44 and attach two things. First, proof of the event: an employer letter confirming retirement or reduced hours, a marriage certificate, a divorce decree or a death certificate. Second, your more recent income: a filed tax return if you have one, or your estimate for the current year. If you use an estimate, you'll send the actual return later, and SSA adjusts if you came in low.

If SSA used incorrect data, or you amended the return for that year, you can ask SSA for a new determination based on the corrected figures. That's a separate request from SSA-44.

Example (hypothetical numbers, to show the method)

Mr. and Mrs. Zhang both turn 65 in 2026 and enroll in Parts B and D. Mrs. Zhang retired years ago, and Mr. Zhang retired in June 2025. Their 2024 joint AGI was $250,000 ($230,000 of wages and $20,000 of interest and dividends), and they also had $30,000 of municipal bond interest.

Their 2024 MAGI is $250,000 plus $30,000, or $280,000, which is joint Tier 2. In 2026 each pays $405.80 a month for Part B ($202.90 above standard) plus $37.50 for Part D. That's ($202.90 + $37.50) × 12 = $2,884.80 extra per person, or $5,769.60 for the couple.

Mr. Zhang's retirement is a work stoppage. They expect only pension and investment income in 2026, with MAGI around $140,000, under $218,000. They file SSA-44 with his employer's retirement letter and their 2026 estimate. If SSA approves, they pay the standard premium for 2026 and save $5,769.60. 2027 will use 2025 income (half a year of wages plus other income); if that's still above the threshold, they can cite the same event again.

Now change the facts: suppose $40,000 of the $280,000 was a Roth conversion and Mr. Zhang hadn't retired. There's no qualifying event, so they pay for 2026. Had he converted only $33,000, MAGI would have been $273,000, in Tier 1, and the couple's extra cost for the year would have been ($81.20 + $14.50) × 12 × 2 = $2,296.80, which is $3,472.80 less than $5,769.60. A $7,000 difference in MAGI changes the premium that much.

No qualifying event? How to plan ahead

Roth conversions: the whole conversion counts in AGI that year. Convert before 63, or spread conversions over several years and keep each year under a tier.

Qualified charitable distributions (QCDs): after 70½, a direct IRA-to-charity transfer of up to $111,000 per person in 2026 stays out of AGI and counts toward your required minimum distribution. Regular charitable gifts are itemized deductions and don't reduce AGI.

Selling assets: a qualifying installment sale spreads the gain across the years you're paid, and capital losses in the same year offset gains. This is about the timing of taxes, not investment advice.

Leave a margin: 2028 premiums will use 2026 income, and the thresholds will be adjusted for inflation by then, so don't plan to land right on the line.

As of November 8, 2026, CMS hasn't announced the 2027 Part B premium or IRMAA thresholds; they usually come out in November. The 2027 Part D national base beneficiary premium has been set at $41.33.

How we can help

YCL handles the tax side of Medicare: checking which year SSA used and whether the numbers are right, preparing SSA-44 with supporting documents, and testing the timing of Roth conversions, asset sales and QCDs against the IRMAA tiers year by year. SSA's decision depends on your facts and documents, and we can't guarantee the result. For enrollment timing, late penalties, HSAs and Medigap, see our Medicare guide; for Roth conversions and RMDs, see the IRA guide. Start with a 15-minute free consultation, or reach us on WeChat at YCLUSA.