What income triggers the Additional Medicare Tax?

by | Dec 6, 2025 | AI Tax Answer Library

Here’s what HIVE AI had to say about “What income triggers the Additional Medicare Tax?”:

What income triggers the Additional Medicare Tax

Overview

The 0.9% Additional Medicare Tax applies when an individual’s earnings exceed filing-status thresholds. It is imposed on:

  • Medicare wages (FICA wages)
  • Self-employment income (subject to SE Medicare tax)
  • Railroad Retirement Tax Act (RRTA) compensation

It does not apply to investment income; that is addressed by the separate Net Investment Income Tax. 1

Filing-status thresholds

  • Married filing jointly: $250,000
  • Married filing separately: $125,000
  • All other filers (single, head of household, qualifying surviving spouse): $200,000

These thresholds are used to determine liability on wages, self-employment income, and RRTA compensation. 2

How it applies by income type

Wages (FICA)

  • You owe the 0.9% tax on FICA Medicare wages above your filing-status threshold.
  • Employers must withhold the 0.9% once your wages paid by that employer exceed $200,000 in the calendar year, regardless of your ultimate filing status or other income. Any remaining liability is settled on your tax return. 3

Self-employment income

  • Compute Additional Medicare Tax on SE income above your filing-status threshold after reducing that threshold by any Medicare wages for the year (not below zero). 4

RRTA compensation

  • Apply the filing-status threshold separately to RRTA compensation; do not combine RRTA with FICA wages for threshold purposes. 5

Statutory foundation

  • For self-employment income, the Additional Medicare Tax is 0.9% on SE income exceeding $250,000 (MFJ), $125,000 (MFS), or $200,000 (others). Thresholds are coordinated with FICA wages by reducing the SE threshold by Medicare wages taken into account under FICA Additional Medicare Tax. 6

Practical notes

  • Having both wages and SE income: calculate the tax on wages over the threshold first; then reduce the SE threshold by total wages and compute tax on SE income over the reduced threshold. 7
  • Employers start withholding once an employee’s wages with that employer exceed $200,000, even if the employee will not owe the tax based on filing status. Any over- or under-withholding is reconciled on the individual return (Form 8959). 3

Sources

1 – IRS.gov – Find out if net investment income tax applies to you 📄 Summarize
2 – IRS.gov – Affordable Care Act tax provisions for individuals 📄 Summarize
3 – IRS – Instruction W-2 and W-3 General Instructions for Forms W-2 and W-3 (Including Forms W-2AS, W-2CM, W-2GU, W-2VI, W-3SS, W-2c, and W-3c) 📄 Summarize
4 – Treasury Regulation 1.1401-1 📄 Summarize
5 – IRS.gov – Questions and answers for the Additional Medicare Tax 📄 Summarize
6 – IRC § 1401(b) 📄 Summarize
7 – IRS.gov Tax Topics 📄 Summarize


Try Your AI Tax Assistant for Free!

Ready to transform your practice with agentic AI in tax? See firsthand how our cutting-edge AI tax tools can revolutionize your approach to tax research and planning.