Medicare Part B
Understand IRMAA Income Thresholds for Medicare Part B and D
Verified against SSA POMS as of July 22, 2026
The short answer
IRMAA (Income-Related Monthly Adjustment Amount) thresholds determine the additional premiums for Medicare Part B and D based on income levels. For 2026, these thresholds vary by tax filing status. For example, for those filing single, the first threshold starts at $109,000. For married couples filing jointly, it begins at $218,000. Medicare Part B IRMAA surcharges can range from 35% to 85% of the true Part B cost, depending on modified adjusted gross income (MAGI). The base national premium for Part B is $202.90 which represents 25% of the true Part B cost. The actual Part B cost is $811.60.
The Centers for Medicare and Medicaid Services (CMS) also calculates the prescription drug (Part D) base premium as well as IRMAA surcharges. The Part D IRMAA surcharge for 2026 starts at $14.50/month for the first IRMAA threshold and increases to $91/month for the highest IRMAA threshold. Prescription drug plans, whether through standalone Part D plans as well as drug plans within Medicare Advantage plans are administered by private insurers.
What is IRMAA?
IRMAA, or Income-Related Monthly Adjustment Amount, is an additional charge to your Medicare Part B and Part D premiums if your income exceeds certain thresholds. This surcharge is calculated based on your Modified Adjusted Gross Income (MAGI) as provided by the IRS. The thresholds and corresponding IRMAA amounts are determined by your IRS tax filing status and are updated annually. MAGI is calculated by adding lines 2a and 11a from the Form 1040. HI 01101.001 provides a detailed description of the IRMAA calculation process.
HI 01101.0012026 IRMAA Thresholds for Medicare Part B
The IRMAA percentages for Medicare Part B in 2026 are as follows: If your tax filing status is 'Single, Head of Household, or Qualifying Widow(er)', the first threshold starts at a MAGI of $109,000, where you will pay 35% of the total Part B cost. The percentage increases to 85% for those with a MAGI over $500,000. For those who are 'Married Filing Jointly', the threshold starts at a MAGI of $218,000, also beginning at the 35% IRMAA level. The maximum percentage of 85% applies to a MAGI of $750,000 or more. HI 01101.031 outlines these thresholds.
HI 01101.031 View source ›| Beneficiaries who file individual tax returns with modified adjusted gross income: | Beneficiaries who file joint tax returns with modified adjusted gross income: | Income-Related Monthly Adjustment Amount | Total Monthly Premium Amount |
|---|---|---|---|
| Less than or equal to $109,000 | Less than or equal to $218,000 | $0.00 | $202.90 |
| Greater than $109,000 and less than or equal to $137,000 | Greater than $218,000 and less than or equal to $274,000 | $81.20 | $284.10 |
| Greater than $137,000 and less than or equal to $171,000 | Greater than $274,000 and less than or equal to $342,000 | $202.90 | $405.80 |
| Greater than $171,000 and less than or equal to $205,000 | Greater than $342,000 and less than or equal to $410,000 | $324.60 | $527.50 |
| Greater than $205,000 and less than $500,000 | Greater than $410,000 and less than $750,000 | $446.30 | $649.20 |
| Greater than or equal to $500,000 | Greater than or equal to $750,000 | $487.00 | $689.90 |
2026 IRMAA Thresholds for Medicare Part D
The income thresholds for Medicare Part D mirror those of Part B. The surcharge amount starts at $14.50/month for the first threshold, rising to $91/month for the highest.
SOURCE GAPHow is MAGI Determined?
MAGI is calculated by taking your adjusted gross income and adding any tax-exempt interest income. This information, usually from two years prior, is supplied by the IRS to determine your IRMAA levels for the given year. See HI 01101.010 for more details.
HI 01101.010 View source ›Appealing IRMAA Determinations
If you believe there is an error in your IRMAA determination due to incorrect MAGI data, you can request a new initial determination from SSA. You will need to provide IRS proof of the error. More details on the appeals process can be found in HI 01140.001.
HI 01140.001 View source ›Frequently asked
What is the initial IRMAA income threshold for singles in 2026?
For 2026, singles with a MAGI over $109,000 are subject to IRMAA for Medicare Part B, starting at 35% of the Part B cost.
How does IRMAA affect my Medicare premiums?
IRMAA is an additional amount to your standard Medicare Part B and D premiums if your income is above certain thresholds as determined by your MAGI.
Is IRMAA based on current income?
No, IRMAA is based on MAGI from tax returns typically filed two years prior to the year the beneficiary
Can I appeal an IRMAA decision?
Yes, if you have proof of incorrect data or a life-changing event affecting your income, you may request a new initial determination.