Additional Medicare Tax Calculator
The Additional Medicare Tax is a 0.9% surtax on earned income above specified thresholds. It applies to wages, tips, and self-employment income only, not to investment income (which is subject to the separate 3.8% Net Investment Income Tax). The threshold is $200,000 for single filers and $250,000 for married filing jointly. Employers withhold the 0.9% tax once cumulative wages paid to an employee exceed $200,000 in a calendar year, but the household threshold may differ from what is withheld, meaning a reconciliation is needed at tax time using IRS Form 8959. This calculator estimates your Additional Medicare Tax based on your filing status and total wages.
Additional Medicare Tax formula
Excess wages = max(0, wages - threshold)
Additional Medicare Tax = excess wages * 0.009
The threshold depends on filing status: $200,000 for single or head of household, $250,000 for married filing jointly, and $125,000 for married filing separately. The tax applies only to the wages that exceed the threshold.
How the Additional Medicare Tax works
- The 0.9% Additional Medicare Tax is an employee-only tax with no employer match.
- Employers withhold it automatically once your wages from that employer exceed $200,000 in a calendar year.
- If your combined household wages exceed your filing-status threshold, you reconcile any under-withholding on Form 8959 and Schedule 2 of Form 1040.
- The thresholds have not been adjusted for inflation since the tax was introduced in 2013.
- Self-employed individuals include Additional Medicare Tax in their self-employment tax calculation via Schedule SE.
Additional Medicare Tax: frequently asked questions
What is the Additional Medicare Tax?
The Additional Medicare Tax is a 0.9% surtax on wages, self-employment income, and railroad retirement compensation above certain thresholds. It was introduced by the Affordable Care Act and has been in effect since 2013.
What are the income thresholds for the Additional Medicare Tax?
The thresholds are $200,000 for single filers, $250,000 for married filing jointly, $125,000 for married filing separately, and $200,000 for head of household. These thresholds are not indexed for inflation.
Does my employer withhold the Additional Medicare Tax?
Employers are required to withhold the 0.9% additional tax on wages paid to an employee that exceed $200,000 in a calendar year, regardless of the employee's filing status. The final liability is reconciled on Form 8959 when you file your tax return.
Does the employer also pay the Additional Medicare Tax?
No. Unlike the regular 1.45% Medicare tax, there is no employer match for the 0.9% Additional Medicare Tax. It is an employee-only tax.
Does the Additional Medicare Tax apply to investment income?
No, the Additional Medicare Tax applies only to wages, tips, and self-employment income. A separate 3.8% Net Investment Income Tax (NIIT) applies to investment income above similar thresholds under IRS Section 1411.
Official sources
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.