Additional Medicare Tax Calculator United States
This Additional Medicare Tax calculator estimates the 0.9% tax on wages and self-employment income above the IRS threshold for your filing status.
What it does
The Additional Medicare Tax Calculator estimates the 0.9% surtax that applies to Medicare wages and self-employment income above a fixed, filing-status threshold.
Data sources & parameters
The figures below drive this calculator. We keep them aligned with the latest official guidance, and each result recalculates automatically whenever a value changes.
| Parameter | Value | Source | Last updated |
|---|---|---|---|
| Additional Medicare Tax rate | 0.009 | irs.gov | Effective 2026-01-01Made open-ended (was valid to 2026-12-31): the 0.9% Additional Medicare Tax rate is fixed by statute (IRC 3101(b)(2)); unchanged for 2027. audit 2026-09-23 |
| Additional Medicare Tax threshold, single | 200,000 | irs.gov | Effective 2026-01-01Made open-ended (was valid to 2026-12-31): the 200,000 threshold is fixed by statute and not indexed (IRC 3101(b)(2)); unchanged for 2027. audit 2026-09-23 |
| Additional Medicare Tax threshold, married filing jointly | 250,000 | irs.gov | Effective 2026-01-01Fix 2026-10-24: the row went live with country_code AU, so Resolver never saw it and the key fell back to the tool.json default. Value unchanged. |
| Additional Medicare Tax threshold, married filing separately | 125,000 | irs.gov | Effective 2026-01-01Fix 2026-10-24: the row went live with country_code AU, so Resolver never saw it and the key fell back to the tool.json default. Value unchanged. |
We always strive to use the latest data for every variable so our results and reports are as accurate as possible. Even so, errors are possible — you should not rely on this tool or its report alone, and we accept no liability for any decision made based on it.
The formula
Additional Medicare Tax = 0.9% × max(0, Medicare wages − threshold)
How it works
It subtracts the threshold for your filing status from your Medicare wages and applies the 0.9% rate to the amount above it.
Where it is used
- Estimating the 0.9% surtax on high wages
- Checking withholding against the actual liability
- Planning around the filing-status threshold
Worked example
With $300,000.00 of Medicare wages as a single filer, the amount over the $200,000 threshold is …, so the 0.9% Additional Medicare Tax is ….
What the Additional Medicare Tax calculator does
The Additional Medicare Tax calculator estimates the 0.9% surtax on higher earners’ Medicare wages and self-employment income. It compares your earnings with the threshold for your filing status and applies the extra rate only to the part above it. Many people first notice this tax when they reconcile their withholding at the end of the year.
The tax was introduced by the Affordable Care Act and took effect in 2013. It is added to the regular 1.45% Medicare tax on all wages, so above the threshold the employee Medicare rate becomes 2.35%. The thresholds do not move with inflation, so the surtax reaches more workers each year as wages rise.
How the 0.9% surtax is calculated
The calculator subtracts the threshold for your filing status from your Medicare wages. If the result is positive, it multiplies that excess by 0.9%. Income at or below the threshold is not subject to the surtax, so the tax is small for someone slightly over the line and grows as wages rise further. The result shows the excess amount and the tax separately.
The thresholds
The thresholds are fixed by statute: $200,000 for single filers and heads of household, $250,000 for married couples filing jointly, and $125,000 for married couples filing separately. Because they are not indexed for inflation, their real value falls every year.
The married filing separately threshold is half the joint one, well below the $200,000 single threshold, which catches some couples by surprise. The same wages can produce a different surtax depending on how you file, so choose your actual filing status in the calculator.
Wages, self-employment income, and withholding
The tax covers Medicare wages, taxable fringe benefits, and self-employment income. If you have both wages and self-employment earnings, they are combined for the threshold test, with wages counted first, and the surtax applies to the combined total above the threshold. Include both to get an accurate estimate.
Employers must withhold the extra 0.9% on any wages above $200,000 they pay to one employee, without regard to filing status or a spouse’s earnings. A married couple filing jointly can end up with too little withheld if each spouse earns under $200,000 but their combined wages exceed $250,000. A single filer with two jobs can end up with too much withheld. The final liability is settled on your tax return with Form 8959, which compares what was withheld with what you owe.
For self-employed workers, the surtax belongs in the money you set aside for quarterly estimated payments. Leaving it out can cause a shortfall and possible penalties.
When to check your position
Run the calculator when you take a higher-paying job, when a spouse’s income lifts your combined wages past the joint threshold, or when you have both a salary and side earnings. Near year-end you can still adjust withholding or make an estimated payment before the tax year closes. Because the thresholds stay flat while wages rise, check each year instead of assuming last year’s result still applies.
This is a planning estimate. Your actual liability depends on your full return, including combined household income, self-employment earnings, and amounts already withheld. For a precise figure, complete Form 8959 or ask a tax professional.
This is general information only and not financial advice.
About This Additional Medicare Tax Calculator
Use this Additional Medicare tax calculator to get an instant, accurate estimate. The figures follow official IRS guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.
Tax year 2026
Frequently asked questions
What is the Additional Medicare Tax?
What are the thresholds?
How is the tax calculated?
Why does my employer withhold it differently?
Does it apply to self-employment income?
Is this the same as the Net Investment Income Tax?
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