W-2

What is the Additional Medicare Tax, and why do I owe it?

It's 0.9% on wages over $200,000, and if you're married, your employer may never have withheld it. Who owes it, how much, and how to stop the surprise.

Updated October 2026 · 5 min read

You found a line on your return called Additional Medicare Tax, and it's asking for money your paychecks never mentioned. It isn't a penalty and you didn't do anything wrong. It's a second Medicare tax that only applies above a certain income, and payroll systems are bad at seeing it coming.

Who owes it

Everyone pays 1.45% Medicare tax on wages. Above a threshold, you pay an extra 0.9% on the wages over the line. The line depends on how you file, not on any one job:

• –Single or head of household: $200,000.
• –Married filing jointly: $250,000, counting both spouses' wages together.
• –Married filing separately: $125,000.

Self-employment income counts toward the same line. These thresholds are fixed in the law and don't rise with inflation, so more people cross them every year. They have been the same since 2013, so if you're catching up on 2022, 2023 or 2024, the numbers on this page are the numbers for that year too.

Why your employer didn't withhold it

Your employer has to start withholding the extra 0.9% once your wages at that job pass $200,000 in the year. It doesn't know your filing status or your spouse's pay. So two common cases slip through:

• –Two earners, each under $200,000. Married, $150,000 each, $300,000 together. You're $50,000 over the joint line, so you owe $450, and neither employer withheld anything.
• –Two jobs in one year. $120,000 at each job means neither one passes $200,000, but you're $40,000 over the single line and owe $360.

When you get money back instead

It can go the other way. If you're married, earn $230,000, and your spouse earns nothing, your employer withheld 0.9% on the $30,000 over $200,000. But your joint line is $250,000, so you owe none. Form 8959 credits that $270 back against your tax.

How it's figured on your return

1. 01Add up Medicare wages from box 5 of every W-2, for both spouses if filing jointly.
2. 02Subtract your threshold. Multiply what's left by 0.9%. That's the tax.
3. 03Compare it with what was withheld. Box 6 minus 1.45% of box 5 is the extra your employer took. The difference is what you owe or get back.
4. 04It all goes on Form 8959, and the total flows to Schedule 2 and your 1040.