Additional Medicare Tax: Form 8959 Basics
Published November 5, 2026
The Additional Medicare Tax is a 0.9% tax. It applies to higher earners. It applies to Medicare wages, railroad retirement compensation, and self-employment income that go above a threshold. The threshold depends on your filing status. IRS: Topic no. 560, Additional Medicare tax
The thresholds
The threshold is $250,000 for married filing jointly. It is $125,000 for married filing separately. It is $200,000 for all other filers, including single and head of household. These amounts are not adjusted for inflation. IRS: Instructions for Form 8959 (2025)
How your employer withholds it
Your employer must withhold the 0.9% tax on your Medicare wages above $200,000 in a calendar year. The employer starts withholding once your wages pass that amount. Withholding is not the final answer. You figure the final tax on Form 8959, so the amount can differ from what was withheld. IRS: Instructions for Form 8959 (2025)
Wages and self-employment income together
If you have both wages and self-employment income, the rules combine them. First, figure the tax on wages above the threshold. Then reduce the threshold by your Medicare wages. Figure the tax on self-employment income above that reduced threshold. The rules are the same whether you have one job or several. Add the Medicare wages from every employer before you compare them with the threshold. Do not count a self-employment loss. IRS: Topic no. 560
Railroad retirement and self-employment
Railroad retirement (RRTA) compensation is compared to the threshold separately. A self-employment loss is not considered for this tax at all. IRS: Topic no. 560
Joint returns
On a joint return, the threshold is $250,000. Both spouses' Medicare wages and self-employment income count toward it. Check both spouses' Forms W-2 before you file. If you file married filing separately, the threshold is $125,000, so the tax can start at a lower income. IRS: Instructions for Form 8959 (2025)
Example
Illustration only, with made-up numbers. Dana is single. Her Medicare wages for 2025 are $230,000 from one employer, and she has no self-employment income. Her threshold is $200,000, so the excess is $30,000. Dana owes $270 of Additional Medicare Tax, which is $30,000 times 0.9%. Her employer should withhold that amount on wages above $200,000.
A second example
Illustration only, with made-up numbers. Ravi is single. He has $150,000 of Medicare wages from an employer and $80,000 on line 6 of Schedule SE. His wages are below $200,000, so the wage part is zero. He reduces the $200,000 threshold by his $150,000 of wages, which leaves $50,000. The self-employment income above $50,000 is $30,000. Ravi owes $270, which is $30,000 times 0.9%.
Where it goes on your return
Attach Form 8959 to your return. The total Additional Medicare Tax goes to Schedule 2 (Form 1040), line 11. Part V of Form 8959 reconciles the tax your employer withheld. IRS: Instructions for Form 8959 (2025)
Records to keep
Keep every Form W-2 you receive. Keep any Form 1099 or your records of self-employment income. If you file a joint return, keep your spouse's forms too, because a joint return combines both spouses' Medicare wages. Keep these forms with your tax file for as long as you keep the return. Compare the Medicare wages on each Form W-2 with your own pay records for the year before you file.
Steps to take
- Add up your Medicare wages for the year from every employer.
- Add your self-employment income, if any, from Schedule SE.
- Compare each total with the threshold for your filing status.
- Figure 0.9% of the amount above the threshold.
- Attach Form 8959 to your return, and check the tax withheld on your Forms W-2.
General information, not advice about your return.
Sources: Sources: IRS, Topic no. 560, Additional Medicare tax (https://www.irs.gov/taxtopics/tc560); IRS, Instructions for Form 8959 (2025) (https://www.irs.gov/pub/irs-pdf/i8959.pdf) This is general information, not advice about your specific return.
