Medicare Additional 0.9% Tax 2027 Calculator
Estimate the 0.9% Additional Medicare Tax owed on wages, SE income, and RRTA compensation for 2027 (Form 8959).
What Is the Additional Medicare Tax?
The 0.9% Additional Medicare Tax applies to W-2 wages, RRTA compensation, and self-employment earnings above $200,000 single / $250,000 MFJ / $125,000 MFS. Enacted under the Affordable Care Act in 2013, the thresholds are NOT indexed for inflation — meaning more taxpayers hit them every year. For 2027, the thresholds remain unchanged. Source: IRC §3101(b)(2), Form 8959. Last updated: May 2026.
How Employer Withholding Works
Employers must withhold the extra 0.9% on wages OVER $200,000 paid to any single employee — regardless of filing status or other income. This creates two common situations: (1) MFJ couples each earning under $200K but jointly over $250K owe additional tax not withheld, (2) MFS filers face mandatory withholding only above $200K but their threshold is $125K, so they owe more.
Self-Employment Income Treatment
Self-employed individuals reduce SE earnings by 7.65% (employer-equivalent FICA) before applying the threshold test. The 0.9% applies to net SE earnings × 92.35% that exceeds the filing-status threshold (after subtracting W-2 wages). Pay via quarterly estimated taxes — no payroll withholding catches it.
Interaction with NIIT
Both the 0.9% Additional Medicare Tax (on earned income) AND the 3.8% NIIT (on investment income) can hit the same taxpayer in the same year. They have similar but separate thresholds. High earners with mixed income should run both calculations — combined burden can be 4.7%+ on the marginal dollar.
Frequently Asked Questions
What is the 2027 Additional Medicare Tax threshold?
$200,000 single/HoH, $250,000 MFJ, $125,000 MFS. These thresholds are NOT indexed for inflation \u2014 they've been unchanged since 2013. The 0.9% tax applies to W-2 wages, RRTA compensation, and self-employment earnings above these amounts.
Does my employer withhold the Additional Medicare Tax?
Yes, but ONLY on wages over $200,000 paid to a single employee \u2014 regardless of filing status. MFJ couples each earning $150K (no withholding) but jointly over $250K still owe the tax. MFS filers face withholding only above $200K despite a $125K threshold.
How does Additional Medicare Tax apply to self-employment income?
Net SE earnings are reduced by 7.65% (employer-equivalent FICA) \u2014 so taxable base is net earnings \u00d7 92.35%. Then subtract W-2 wages from your threshold to get the SE threshold remaining, and apply 0.9% to the excess. Pay via Form 1040-ES quarterly.
Can I get a refund of withheld Additional Medicare Tax?
Yes. If your employer withheld 0.9% on wages over $200K but your actual liability (based on filing status + total income) is lower, you reconcile on Form 8959 and any over-withholding becomes part of your refund. Common for two-income couples below the $250K MFJ threshold.
Is Additional Medicare Tax deductible above-the-line?
No. Unlike the employer share of regular Medicare, the 0.9% Additional Medicare Tax is NOT deductible. It's a pure tax \u2014 not a payroll cost. Self-employed individuals cannot deduct half of it on Form 1040 the way they do regular SE tax.
Does the OBBB law change Additional Medicare Tax in 2027?
No. OBBB did not modify IRC \u00a73101(b)(2). The 0.9% rate and unchanged $200K/$250K/$125K thresholds remain in effect for 2027. Congressional proposals to index thresholds for inflation have not been enacted.