Additional Medicare Tax Calculator
The Additional Medicare Tax is a 0.9 percent tax on Medicare wages and self-employment income above a threshold that depends on your filing status. It applies on top of the regular 1.45 percent Medicare tax and is reported on Form 8959. The thresholds (for example, $200,000 single, $250,000 married filing jointly) are fixed by statute and not adjusted for inflation. This calculator combines your wages and self-employment income, subtracts your threshold, and applies the 0.9 percent rate to the excess.
Additional Medicare Tax formula
Combined income = Medicare wages + self-employment income
Amount over threshold = max(0, combined income - threshold)
Additional Medicare Tax = amount over threshold * 0.009
Regular Medicare tax = combined income * 0.0145
Only income above your filing-status threshold is subject to the extra 0.9 percent. The regular 1.45 percent Medicare tax applies to all Medicare wages and is shown for comparison.
Additional Medicare Tax context
- The rate is 0.9 percent on income above the threshold, reported on Form 8959.
- Thresholds are $200,000 single, $250,000 married filing jointly, and $125,000 married filing separately.
- The thresholds are set by statute and are not indexed for inflation.
- Employers withhold the tax on wages over $200,000 regardless of filing status.
- It applies on top of the regular 1.45 percent Medicare tax.
Additional Medicare Tax: frequently asked questions
What is the Additional Medicare Tax?
The Additional Medicare Tax is a 0.9 percent tax on Medicare wages, railroad retirement compensation, and self-employment income above a threshold based on filing status. It was created by the Affordable Care Act and is reported on Form 8959. It applies on top of the regular 1.45 percent Medicare tax.
What are the income thresholds?
The thresholds are set in statute and are not indexed for inflation: $250,000 for married filing jointly, $125,000 for married filing separately, and $200,000 for single, head of household, and qualifying surviving spouse. Enter the threshold for your filing status; this calculator defaults to the $200,000 single threshold.
How is the tax calculated?
Add your Medicare wages and self-employment income, subtract your filing-status threshold, and multiply the excess by 0.9 percent. For example, $260,000 of wages for a single filer exceeds the $200,000 threshold by $60,000, producing an additional tax of $540. Only the amount over the threshold is taxed.
Does my employer withhold this tax?
Employers must withhold the 0.9 percent Additional Medicare Tax on wages over $200,000 in a calendar year, regardless of your filing status. If your actual threshold differs (for example, married filing jointly), you may owe more or get a credit when you file Form 8959 with your return.
Is self-employment income included?
Yes. The tax applies to the combined total of Medicare wages and self-employment income above your threshold, but wages are counted first. Self-employment income is reduced by any threshold remaining after wages. This calculator combines both into a single excess-over-threshold computation.
Official sources
- U.S. Internal Revenue Service: About Form 8959, Additional Medicare Tax.
- U.S. Internal Revenue Service: IRS.gov.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.