U.S. · Form 8959 line 24
Form 8959 line 24 total Additional Medicare Tax withholding.
Part V of Form 8959: how much of the Medicare tax on your W-2 was actually the 0.9% additional tax.
Line 24 is the total Additional Medicare Tax withholding: line 22 plus line 23. Line 22 is W-2 box 6 minus 1.45% of box 5, not below zero; line 23 is Additional Medicare Tax withheld on railroad retirement (RRTA) compensation from W-2 box 14. Include line 24 with federal income tax withholding on Form 1040, 1040-SR or 1040-NR, line 25c.
Part V, lines 19 to 24
Result
Part V, line by line
| Line | What it is (2025 form) |
|---|---|
| 19 | Medicare tax withheld from Form W-2, box 6; add all W-2s. Also include uncollected Medicare tax in box 12 codes B and N |
| 20 | The amount from line 1 (Medicare wages and tips) |
| 21 | Line 20 times 1.45% (0.0145): your regular Medicare tax withholding on Medicare wages |
| 22 | Line 19 minus line 21, not below zero: Additional Medicare Tax withholding on Medicare wages |
| 23 | Additional Medicare Tax withholding on RRTA compensation from W-2 box 14 |
| 24 | Add lines 22 and 23: total Additional Medicare Tax withholding |
Who gets Additional Medicare Tax withheld
Your employer is responsible for withholding the 0.9% tax on Medicare wages or RRTA compensation it pays you above $200,000 in a calendar year, regardless of your filing status and regardless of what any other employer pays you. You cannot ask your employer to stop withholding it when required. Your actual liability uses the threshold for your filing status ($250,000 married filing jointly, $125,000 married filing separately, $200,000 otherwise), so withholding can be more or less than the tax on lines 7, 13 and 17. If you do not owe Additional Medicare Tax, you can claim a credit for what was withheld by filing Form 8959.
Worked example
A single filer has $250,000 of Medicare wages (box 5) and $4,075 of Medicare tax withheld (box 6). Line 21 is $250,000 times 1.45% = $3,625, so line 22 is $450 and, with no RRTA compensation, line 24 is $450. That matches the tax on line 7: ($250,000 - $200,000) times 0.9% is $450. Amounts are illustrative.
What this page does not do
It does not compute the Additional Medicare Tax owed (lines 1 to 18). For self-employment income see the Additional Medicare Tax self-employed calculator.
Sources
- Instructions for Form 8959 (2025): Part V instructions, the employer withholding rules and the line 24 return reference. Read November 2, 2026.
- Form 8959 (2025): The exact wording of lines 19 to 24 and the filing-status amounts. Read November 2, 2026.
These are the tax year 2025 edition instructions and forms (published for returns filed in 2026). The IRS revises them each year, so thresholds, line numbers and limits can change; check the current edition before relying on a figure.
Frequently asked questions
What is Form 8959 line 24?
Total Additional Medicare Tax withholding: the sum of line 22 (on Medicare wages) and line 23 (on RRTA compensation).
Where does line 24 go on my return?
Include it with federal income tax withholding on Form 1040, 1040-SR or 1040-NR, line 25c. Form 1040-SS filers enter it on line 11a of Part I.
How do I find the Additional Medicare Tax part of box 6?
Subtract 1.45% of box 5 (line 21) from box 6 (line 19). If the result is zero or less, line 22 is zero.
When does an employer withhold the 0.9%?
On Medicare wages or RRTA compensation paid above $200,000 in a calendar year, regardless of filing status or other employers.
Can I stop my employer from withholding it?
No. If you do not owe the tax you can claim the withheld amount as a credit by filing Form 8959.
Not tax or legal advice
This page summarizes IRS instructions and is not tax, legal or financial advice. A CPA, enrolled agent or the IRS can confirm what applies to your situation. Everything runs in your browser; nothing you enter is sent anywhere.