Medicare Tax Calculator

Free 2025 Medicare tax calculator. Compute your 1.45% Medicare tax, additional 0.9% Medicare surtax, and Net Investment Income Tax (NIIT) on wages and investment income.

About the Medicare Tax Calculator

The Medicare Tax Calculator computes your total Medicare contribution for 2025, including the base 1.45% rate on all wages and the additional 0.9% surtax on earnings above $200,000 (single) or $250,000 (married filing jointly).

Unlike Social Security tax, Medicare has no wage base cap — every dollar of wages is taxed. High earners also face the 3.8% Net Investment Income Tax (NIIT) on investment income, which effectively extends Medicare-style taxation to passive income.

Enter your wages, filing status, and investment income to see your complete Medicare tax picture including employer contributions and take-home impact. High earners face a triple layer of Medicare-related taxes: the standard 1.45% on all wages, the Additional Medicare Tax of 0.9% on wages exceeding $200,000 for single filers, and the 3.8% Net Investment Income Tax on investment income above the same thresholds. Understanding all three layers helps you estimate your true effective tax rate and plan withholding or estimated payments accurately.

Why Use This Medicare Tax Calculator?

Medicare taxes have multiple layers that many taxpayers overlook. This calculator shows the base tax, additional Medicare surtax, and potential NIIT in one view so you can understand your full Medicare-related tax burden and plan withholding accordingly. This complete view prevents unpleasant surprises and helps high earners plan quarterly estimated payments more accurately.

How to Use This Calculator

  1. Enter your annual gross wages.
  2. Select your filing status.
  3. Optionally enter net investment income for NIIT calculation.
  4. View your base Medicare tax, additional Medicare tax, and NIIT.
  5. Review the threshold comparison to see how far above or below the surtax trigger you are.

Formula

Base Medicare Tax = Gross Wages × 1.45% Additional Medicare Tax = Max(0, Wages − Threshold) × 0.9% Thresholds: $200,000 (Single/HoH), $250,000 (MFJ), $125,000 (MFS) NIIT = Net Investment Income × 3.8% (if MAGI > threshold)

Example Calculation

Result: Total Medicare-related taxes: $6,350

Base Medicare = $300,000 × 1.45% = $4,350. Additional Medicare = ($300,000 − $200,000) × 0.9% = $900. NIIT = $50,000 × 3.8% = $1,900 (MAGI $350,000 exceeds $200,000 threshold, lesser of investment income or excess). Total = $4,350 + $900 + $1,900 = $7,150.

Tips & Best Practices

Understanding the Three Medicare Taxes

Most workers see only the 1.45% line on their pay stub, but there are actually three Medicare-related taxes: the base 1.45% tax on all wages, the 0.9% Additional Medicare Tax on wages above the threshold, and the 3.8% Net Investment Income Tax on passive income for high earners.

Who Pays the Additional Medicare Tax?

The 0.9% surtax is withheld by employers once wages exceed $200,000 in a calendar year, regardless of filing status. If you're married filing jointly, your actual threshold is $250,000, so you may be over-withheld or under-withheld. You reconcile on Form 8959 when you file.

NIIT Planning Strategies

Since NIIT applies to the lesser of net investment income or MAGI excess, strategies to reduce it include tax-exempt municipal bonds (whose income is excluded from NIIT), installment sales to spread capital gains over years, Roth conversions to reduce future investment income, and harvesting losses to offset capital gains.

Frequently Asked Questions

What is the additional Medicare tax?

The additional Medicare tax is an extra 0.9% that applies to wages exceeding $200,000 (single), $250,000 (MFJ), or $125,000 (MFS). It was introduced by the Affordable Care Act in 2013 and is paid only by employees, not matched by employers.

What is the Net Investment Income Tax (NIIT)?

The NIIT is a 3.8% tax on the lesser of your net investment income or the amount by which your MAGI exceeds the threshold ($200,000 single, $250,000 MFJ). It applies to interest, dividends, capital gains, rental income, and other passive income.

Does my employer pay Medicare tax too?

Yes, your employer pays a matching 1.45% base Medicare tax on all your wages. However, the employer does not pay the additional 0.9% surtax — that is solely the employee's responsibility. Self-employed individuals pay both halves (2.9% + 0.9% if applicable).

Are the Medicare surtax thresholds adjusted for inflation?

No. The $200,000/$250,000/$125,000 thresholds for the additional Medicare tax and the NIIT thresholds have remained unchanged since 2013. More taxpayers fall above these thresholds each year due to wage growth.

Can I deduct Medicare tax on my tax return?

Employees cannot deduct the Medicare tax they pay. However, self-employed individuals can deduct the employer-equivalent portion of their self-employment tax (half of the 2.9% Medicare rate) as an above-the-line deduction on Schedule SE.

How does Medicare tax differ from Social Security tax?

Social Security is taxed at 6.2% but capped at $176,100 (2025). Medicare is taxed at 1.45% with no cap, plus an additional 0.9% on high earners. Together they form the FICA taxes withheld from your paycheck.

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