Additional Medicare Tax (0.9%) Exposure Calculator
Example: Annual W-2 wages: 200000 $ · Net self-employment income: 0 $ · Filing status (0 = Single, 1 = Married Filing Jointly): 0
| Additional Medicare Tax owed (0.9%) | $0 |
| Income threshold for your filing status | $200,000 |
| Income above threshold subject to surtax | $0 |
| Effective total Medicare tax rate on all income | 1.45% |
Worked example
A single filer with $240,000 in W-2 wages: $240,000 − $200,000 threshold = $40,000 subject to the 0.9% surtax. Additional Medicare Tax: $40,000 × 0.9% = $360. This often catches people by surprise at filing — their employer withheld 1.45% Medicare on all wages, but the 0.9% extra only applies to amounts above $200,000, and reconciliation happens on Form 8959. A dual-income couple each earning $150,000 combined at $300,000 would owe 0.9% on $50,000 = $450 despite neither employer withholding it.
Frequently asked questions
Why might I owe this at filing even if my employer withheld from my paycheck?
Employers withhold the 0.9% Additional Medicare Tax only when an individual employee's wages from that employer exceed $200,000 in a calendar year. If you work two jobs earning $130,000 each, neither employer withholds the surtax — but your combined income of $260,000 exceeds the $200,000 threshold. The $60,000 excess is calculated on Form 8959 at tax time.
Does this apply to investment income?
No — the 0.9% Additional Medicare Tax applies only to wages and self-employment income. Investment income (dividends, interest, capital gains, rental income) is subject to the separate 3.8% Net Investment Income Tax, not the 0.9% Medicare surtax. Use the NIIT calculator for investment income.
Is there a way to reduce Additional Medicare Tax?
Pre-tax 401(k) or 403(b) contributions reduce W-2 wages for FICA purposes — which reduces the income subject to the threshold comparison. However, the Additional Medicare Tax has no wage base cap (unlike Social Security), so higher earnings always trigger it once above the threshold. Pre-tax retirement contributions are the most direct reduction lever.