US Additional Medicare Tax Calculator: 0.9% on High Earners
Work out the US Additional Medicare Tax — the extra 0.9% high earners owe on wages and self-employment income above a threshold — on the portion of your earnings that exceeds it.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Additional Medicare Tax | Excess net of tax |
|---|---|---|
| 0.9% of $50,000 over ($450) | 450 | 49,550 |
| 0.9% of $100,000 over | 900 | 99,100 |
| 0.9% of $25,000 over | 225 | 24,775 |
| 0.9% of $300,000 over | 2,700 | 297,300 |
How This Calculator Works
Enter the 0.9% rate and your earnings above your filing-status threshold (not your full income — only the excess). The calculator returns the Additional Medicare Tax. The thresholds are $200,000 for single filers and $250,000 for married filing jointly (these are not indexed for inflation), so only income above those amounts is subject to the extra 0.9%.
The Formula
Percentage of an Amount
Amount is the base value, Percentage is the rate applied to it
Worked Example
If your earnings exceed the threshold by $50,000, the Additional Medicare Tax is $450 (0.9% of $50,000). This tax is on top of the regular 1.45% Medicare portion of FICA — so wages above the threshold are effectively taxed at 2.35% for Medicare (1.45% + 0.9%). It applies to wages, compensation, and self-employment income above the threshold, but unlike the employer-matched regular Medicare tax, there is no employer match on the additional 0.9% — the employee bears it entirely.
Key Insight
The Additional Medicare Tax is a 0.9% surtax introduced under the Affordable Care Act, and a few specifics matter for high earners. It applies only to earned income (wages, RRTA compensation, and self-employment income) above the threshold for your filing status: $200,000 single/head of household, $250,000 married filing jointly, and $125,000 married filing separately — and notably these thresholds are not indexed for inflation, so over time more taxpayers cross them. Employers must begin withholding the extra 0.9% once an employee's wages from that employer exceed $200,000, regardless of filing status — which means withholding can be too much or too little versus your actual liability (e.g. a married couple each earning $150,000 has $300,000 combined, owing the tax on $50,000, but neither employer withholds it; conversely a single high earner may have it over-withheld), so it's reconciled on your tax return. Don't confuse it with the separate 3.8% Net Investment Income Tax (NIIT), which applies to investment income above similar thresholds — they're two different ACA surtaxes, and a high earner can owe both on different income types. This calculator computes the 0.9% on the excess earnings you enter; to find your actual liability, determine how much of your earned income exceeds your filing-status threshold and apply 0.9% to that amount. For self-employed taxpayers, the 0.9% is in addition to the regular Medicare portion of self-employment tax on income above the threshold. Confirm current thresholds and rules with the IRS or a tax professional.
Frequently Asked Questions
How is the Additional Medicare Tax calculated?
Multiply your earnings above the filing-status threshold by 0.9%. If you're $50,000 over the threshold, the tax is $450. It applies only to the excess above the threshold, not your entire income.
What are the thresholds?
$200,000 for single and head-of-household filers, $250,000 for married filing jointly, and $125,000 for married filing separately. Only earned income (wages and self-employment income) above your threshold is subject to the extra 0.9%. The thresholds are not indexed for inflation.
Is this on top of regular Medicare tax?
Yes. It's in addition to the regular 1.45% Medicare portion of FICA, so wages above the threshold are effectively taxed at 2.35% for Medicare (1.45% + 0.9%). Unlike the regular Medicare tax, there's no employer match on the additional 0.9% — the employee bears it entirely.
Why might my withholding be wrong?
Employers withhold the 0.9% once your wages from that employer exceed $200,000, regardless of filing status. So a married couple each earning $150,000 owes the tax but has none withheld, while a single high earner might have it over-withheld. It's reconciled on your tax return, where the actual liability is calculated.
Is this the same as the 3.8% Net Investment Income Tax?
No — they're two different ACA surtaxes. The Additional Medicare Tax (0.9%) applies to earned income above the threshold; the Net Investment Income Tax (3.8%) applies to investment income above similar thresholds. A high earner can owe both, on different types of income. Don't confuse them.
Related Calculators
Methodology & Review
The tax is the 0.9% Additional Medicare Tax applied to the earnings above the filing-status threshold; the remainder is that excess net of the tax. Enter only the wages/self-employment income above the threshold. It does not compute the threshold itself or the separate 3.8% Net Investment Income Tax.
Written by Ugo Candido · Last updated May 22, 2026.