Medicare Premium Calculator: What Income is Used?

Estimate your 2026 Medicare Part B and Part D premiums based on your 2024 income.

IRMAA Calculator

What Income is Used to Calculate Medicare Premiums?

The income used to calculate Medicare premiums is your Modified Adjusted Gross Income (MAGI) from your IRS tax return from two years prior. This means your 2026 Medicare premiums are determined by the MAGI on your 2024 tax return. If your income exceeds certain thresholds, you’ll pay the standard Medicare Part B premium plus an additional amount known as the Income-Related Monthly Adjustment Amount, or IRMAA. This surcharge applies to both Part B (medical insurance) and Part D (prescription drug coverage) premiums.

This system ensures that higher-income beneficiaries contribute a larger share towards their healthcare costs. The Social Security Administration (SSA) determines your IRMAA annually based on the income data it receives from the IRS.

Medicare IRMAA Formula and Explanation

There isn’t a continuous mathematical formula for the what income is used to calculate medicare premiums. Instead, the SSA uses a tiered bracket system. Your MAGI and tax filing status determine which bracket you fall into. Each bracket has a corresponding set monthly premium for Part B and a fixed adjustment amount for Part D.

The core concept is: MAGI = Adjusted Gross Income (AGI) + Tax-Exempt Interest. Other less common items like foreign earned income may also be added back. The table below shows the 2026 IRMAA brackets based on 2024 income.

2026 Medicare IRMAA Brackets (Based on 2024 MAGI)

Filing Status	Modified Adjusted Gross Income (MAGI)	Total Monthly Part B Premium	Monthly Part D Adjustment
Individual	≤ $109,000	$202.90 (Standard Premium)	$0.00 + Plan Premium
Married, Jointly	≤ $218,000	$202.90 (Standard Premium)	$0.00 + Plan Premium
Individual	$109,001 – $137,000	$284.10	$14.50 + Plan Premium
Married, Jointly	$218,001 – $274,000	$284.10	$14.50 + Plan Premium
Individual	$137,001 – $171,000	$405.80	$37.50 + Plan Premium
Married, Jointly	$274,001 – $342,000	$405.80	$37.50 + Plan Premium
Individual	$171,001 – $205,000	$527.50	$60.40 + Plan Premium
Married, Jointly	$342,001 – $410,000	$527.50	$60.40 + Plan Premium
Individual	$205,001 – < $500,000	$649.20	$83.30 + Plan Premium
Married, Jointly	$410,001 – < $750,000	$649.20	$83.30 + Plan Premium
Individual	≥ $500,000	$689.90	$91.00 + Plan Premium
Married, Jointly	≥ $750,000	$689.90	$91.00 + Plan Premium
Married, Separately	$109,001 – < $391,000	$649.20	$83.30 + Plan Premium
Married, Separately	≥ $391,000	$689.90	$91.00 + Plan Premium

Data is based on official CMS releases for 2026. Find more about {related_keywords}.

Practical Examples

Example 1: Single Filer

Jane is a single retiree. Her 2024 tax return shows a MAGI of $125,000.

• Inputs: Filing Status = Single, MAGI = $125,000
• Bracket: $109,001 – $137,000
• Results: Her monthly Part B premium for 2026 will be $284.10, and she will have a $14.50 monthly adjustment added to her Part D plan’s premium.

Example 2: Married Filing Jointly

John and Mary file their taxes jointly. Their combined MAGI for 2024 was $280,000.

• Inputs: Filing Status = Married Filing Jointly, MAGI = $280,000
• Bracket: $274,001 – $342,000
• Results: Their monthly Part B premium for 2026 will be $405.80 each, and they will each have a $37.50 monthly adjustment added to their respective Part D plan premiums. Learn more about {related_keywords}.

How to Use This Medicare Premium Calculator

Using this calculator is a straightforward process to estimate your future Medicare costs.

1. Select Your Filing Status: Choose the tax filing status from your 2024 tax return (e.g., Single, Married Filing Jointly).
2. Enter Your MAGI: Find your Modified Adjusted Gross Income on your 2024 IRS tax return and enter it into the input field. If you don’t know it, you can approximate it by adding your Adjusted Gross Income (AGI) and any tax-exempt interest you received.
3. Review Your Results: The calculator will instantly display your estimated total monthly premium, breaking it down into the Part B premium and the Part D adjustment amount.
4. Interpret the Output: The “Part B Premium” is your total monthly cost for medical insurance. The “Part D Adjustment” is an extra amount added to the specific premium of the prescription drug plan you choose.

Key Factors That Affect Your Medicare Premiums

Several key factors determine the income used to calculate medicare premiums and whether you’ll pay more than the standard amount.

• Modified Adjusted Gross Income (MAGI): This is the primary driver. Higher income directly leads to higher premiums.
• Tax Filing Status: The income brackets are different for individuals, those married filing jointly, and those married filing separately.
• Two-Year Lookback: Premiums are always based on your tax return from two years ago, which can be a surprise if your income has changed recently.
• Life-Changing Events: A significant decrease in income due to events like retirement, divorce, or the death of a spouse may qualify you to appeal your IRMAA and have it recalculated based on more current income. This requires submitting Form SSA-44 to the Social Security Administration.
• Annual Bracket Adjustments: The income thresholds for IRMAA are adjusted each year for inflation, so the brackets change over time.
• Late Enrollment Penalties: It’s crucial to note that IRMAA is separate from any late enrollment penalties you might incur for Part B or Part D. These penalties can be added on top of your IRMAA-adjusted premium. More details on {related_keywords} are available.

Frequently Asked Questions (FAQ)

What is IRMAA?

IRMAA stands for Income-Related Monthly Adjustment Amount. It’s an extra charge that higher-income beneficiaries pay for Medicare Part B and Part D. It is not a penalty, but rather a legislated requirement for those with the ability to pay more to contribute more.

How do I find my MAGI for Medicare purposes?

For most people, your MAGI is your Adjusted Gross Income (AGI) from your IRS Form 1040, plus any tax-exempt interest income (like from municipal bonds). You can find your AGI on line 11 of your Form 1040.

What if my income was high two years ago but is much lower now?

You can request a new determination from the Social Security Administration if you’ve had a “life-changing event” that caused your income to decrease. Qualifying events include marriage, divorce, death of a spouse, work stoppage or reduction, and loss of an income-producing property. You will need to file Form SSA-44, “Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event”.

Does everyone pay an IRMAA?

No. Most Medicare beneficiaries pay only the standard Part B premium. In 2026, IRMAA only affects individuals with a 2024 MAGI above $109,000 and married couples with a MAGI above $218,000.

Is the Part D adjustment my total drug plan cost?

No. The Part D IRMAA is an extra amount you pay in addition to your monthly premium for your specific Part D plan. You still have to pay the plan’s premium directly to the insurance company.

How will I know if I have to pay IRMAA?

The Social Security Administration will send you a letter, called an initial determination notice, informing you of your new premium amount if you are subject to IRMAA. Check out our guide on {related_keywords} for more info.

Are Medicare Part A (Hospital Insurance) premiums based on income?

No. Most people receive Part A premium-free because they or their spouse paid sufficient Medicare taxes while working (typically for 10 years). If you do have to buy Part A, the premium is a flat rate and not based on your income.

How can I lower my MAGI to reduce my premiums?

Strategic financial planning can help. Strategies include contributing to tax-deferred retirement accounts like a traditional 401(k) or IRA, utilizing Roth conversions strategically in lower-income years, and managing capital gains. Consulting a financial advisor specializing in retirement is recommended. Explore options with {related_keywords}.