How Medicare IRMAA Works: The 2026 Part B and Part D Income Surcharges

If your income is above a set line, Medicare charges you more for Part B and Part D. That extra charge is called IRMAA, and the amount depends on a tax return you filed two years earlier.

What IRMAA Is and Who Pays It

IRMAA stands for Income-Related Monthly Adjustment Amount. It is a surcharge that higher-income people pay on top of their standard Medicare premiums. It applies to both Part B, which covers doctor visits, and Part D, which covers prescription drugs.

Most people never pay IRMAA. The standard 2026 Part B premium is $202.90 a month, and anyone at or below the first income line pays only that. You owe IRMAA only when your income rises above that first line.

The charge is based on your modified adjusted gross income, or MAGI. For IRMAA, MAGI is your adjusted gross income plus any tax-exempt interest. You can estimate your own surcharge with our Medicare IRMAA calculator before your premiums are set.

How the Two-Year MAGI Lag Works

Here is the part that surprises people. IRMAA is not based on your income this year. It is based on your tax return from two years earlier, because that is the most recent return the IRS has shared with Social Security when premiums are set.

So your 2026 IRMAA comes from the MAGI on your 2024 tax return. If your income was high in 2024 but dropped in 2025, you still pay based on 2024 until the next year catches up. The timeline below shows the lag.

This lag matters most around big life changes. A final high-earning year before retirement can raise your Medicare cost two years later, even after your paycheck stops. The good news is you can appeal that in some cases, which we cover below.

The 2026 Part B and Part D Surcharge Tiers

IRMAA uses six income tiers. Tier one is the standard premium with no surcharge. Each tier above that adds more to both your Part B premium and your Part D premium. The table shows the 2026 amounts and the income lines for each filing status.

Married filing separately works differently. If you file separately and lived with your spouse, a MAGI of $109,000 or less keeps the standard $202.90 and $0 add-on. Above $109,000 and under $391,000, you pay $649.20 for Part B plus $83.30 for Part D. At $391,000 or more, you pay $689.90 plus $91.00. See our Social Security taxable calculator for a related income question.

Why IRMAA Is a Cliff, Not a Slope

IRMAA is a cliff. One dollar over a threshold moves you into the next tier, and the whole higher surcharge applies. It does not phase in gradually, so a tiny income difference can raise your yearly cost by hundreds of dollars.

Picture a single filer with a MAGI of exactly $137,000. They sit in tier two. A filer at $137,001 lands in tier three and pays the full tier-three premium. The step chart shows how each tier jumps up at the line.

Because the jump is sharp, careful planning helps near a line. Choices like the timing of a Roth conversion or a capital gain can push your MAGI over a threshold. The senior deduction calculator can help you see how deductions shape taxable income.

A Worked Example: Single Filer at $150,000

Let us run a real case. Take a single filer whose 2024 MAGI was $150,000. That amount is over $137,000 and at or under $171,000, so it lands in tier three for 2026. Here is how the yearly surcharge adds up.

1. Find the Part B premium. Tier three is $405.80 a month. The standard premium is $202.90, so the surcharge part is $405.80 minus $202.90, which is $202.90 a month.
2. Turn Part B into a year. Multiply the $202.90 monthly surcharge by 12. That is $2,434.80 of extra Part B cost for the year.
3. Add the Part D surcharge. Tier three adds $37.50 a month for Part D. Multiply by 12 to get $450.00 for the year.
4. Total the IRMAA. Add $2,434.80 and $450.00. The full IRMAA surcharge is $2,884.80 for the year, on top of the standard premiums.

That is real money on top of the base premiums. Change the income or the filing status and the tier moves. The IRMAA calculator runs every tier for you, so you can test a number without doing the arithmetic by hand.

How to Appeal IRMAA With Form SSA-44

You can ask Social Security to lower or drop your IRMAA after a life-changing event. The form is SSA-44, and it exists because the two-year lag can charge you on income you no longer earn. Social Security reviews the event and your newer income.

Qualifying events are specific. They include things like retirement that cut your work income, marriage or divorce, the death of a spouse, or the loss of a pension. A simple drop in investment income by itself does not usually qualify.

• Gather proof. Keep documents that show the event and your newer, lower income, such as a retirement letter or a death certificate.
• File SSA-44. Complete the Medicare Income-Related Monthly Adjustment Amount Life-Changing Event form and send it with your evidence.
• Expect a review. Social Security decides whether to use a more recent year instead of the two-year-old return.

Planning ahead for retirement income also helps you avoid a surprise surcharge. Our retirement calculator can map how withdrawals might shape your MAGI in future years.

FAQs About Medicare IRMAA

Sources and Further Reading

This article is general education, not financial, tax or investment advice. Figures and limits can change; confirm current amounts on the official source before you rely on them. Reviewed for accuracy by Prof. Dr. Khalil Mudassar, PhD. Last updated 2026-10-06. MultiCalculators is not affiliated with or endorsed by the IRS, CMS, SSA or BLS.