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Official form guide
Form 8959: Additional Medicare Tax
IRS Form 8959 is used to calculate the 0.9% Additional Medicare Tax on wages, self‑employment income, and RRTA compensation that exceed the $200,000 threshold, and must be filed by taxpayers who owe or have had this tax withheld.
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IRS Form 8959 - Additional Medicare Tax
IRS Form 8959 is used to calculate the 0.9% Additional Medicare Tax on wages, self‑employment income, and RRTA compensation that exceed the $200,000 threshold, and must be filed by taxpayers who owe or have had this tax withheld.
Risk Radar
Scan points- 1Omitting the Additional Medicare Tax withheld can trigger a penalty.
- 2Failing to multiply Medicare wages by 0.9% on Line 7, resulting in an incorrect tax amount.
- 3Leaving Part V blank when Medicare tax was withheld, preventing proper withholding reconciliation.
- 4Not reporting self‑employment income on Line 8, which omits taxable income from the calculation.
- 5Omitting RRTA compensation on Line 14 (or spouse’s amount) when applicable, leading to underpayment.
Plain English
Form 8959 tells you how much extra Medicare tax you need to pay on high earnings. You add up wages, self‑employment earnings, and railroad compensation that go over $200,000, apply the 0.9% rate, and report the total with your tax return.
Submission Date
- Filing date: 2025-12-04 14:00:41
- Preparation window: collect IDs, supporting records, and signatures in advance.
- Final review: verify names, dates, and required fields before submission.
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What this form is for
- Use this form when you have Medicare wages, RRTA compensation, or self‑employment income that exceed the applicable threshold ($200,000 for single, head of household, qualifying surviving spouse; $250,000 married filing jointly; $125,000 married filing separately) and you owe or have had Additional Medicare Tax withheld.
- Do not use it when your Medicare wages, RRTA compensation, and self‑employment income are all below the thresholds for your filing status.
- Check Form 1040‑ES instead when you need to make estimated tax payments for Additional Medicare Tax.
Form selector
Use this form or another form?
Filing an individual income tax return
Form 8959 must be attached to the individual return
✓ Confirm you are using the correct 1040 version for 2026
Filing a nonresident alien return
Nonresident returns also require attachment of Form 8959 if tax applies
✓ Verify filing status matches nonresident requirements
Expecting to owe Additional Medicare Tax and need to make payments
Estimated payments cover the tax due before filing
✓ Calculate estimated tax using the worksheet in Pub. 505
Deadline or filing window
Not stated in the official source.
Checklist
What you need before filling it out
Medicare wages and tips (Form W-2 box 5)
Form W-2 (or equivalent territorial forms) · Box 5 of Form W-2
RRTA compensation (Form W-2 box 14)
Form W-2 (or equivalent) · Box 14 of Form W-2
Self‑employment income
Schedule SE or self‑employment earnings records · Schedule SE attached to Form 1040
Unreported tips (Form 4137 line 6)
Form 4137 · Line 6 of Form 4137
Wages from Form 8919 (line 6)
Form 8919 · Line 6 of Form 8919
Before you submit
- 1Enter total Medicare wages and tips from all Form W-2 box 5 on line 1.
- 2Enter unreported tips from Form 4137 line 6 on line 2.
- 3Enter wages from Form 8919 line 6 on line 3.
- 4Add lines 1 through 3 and record the sum on line 4.
- 5Enter the threshold amount for your filing status on line 5.
- 6Calculate Additional Medicare Tax on the amount exceeding the threshold.
- 7Attach Form 8959 to the appropriate Form 1040, 1040‑SR, 1040‑NR, or 1040‑SS.
- 8Sign the form as required.
- 9Keep a copy of the completed Form 8959 for your records.
How to file this form
- 1Gather all Forms W-2 (including W-2AS, W-2CM, W-2GU, W-2VI, 499R-2/W-2PR) and any Form 4137 or Form 8919.
- 2Calculate total Medicare wages, tips, RRTA compensation, and self‑employment income.
- 3Complete Part I of Form 8959 by entering amounts on lines 1‑5 and computing the tax.
- 4Attach Form 8959 to your filed Form 1040 (or 1040‑SR, 1040‑NR, 1040‑SS).
- 5Sign the return and retain a copy of Form 8959 as proof of filing.
Known limitations
- 1Form 8959 does not apply to nonresident aliens and U.S. citizens living abroad — source p.2.
- 2Additional Medicare Tax is not assessed on RRTA compensation unless a single Form W‑2 shows box 14 over $200,000 — source p.1.
- 3For self‑employment income, the threshold is reduced by total Medicare wages but never below zero — source p.2.
Field map
Compact field-by-field guide
Entity Info
1 items
Name and taxpayer ID of the entity claiming the credit.
Credit Info
1 items
Type of credit or incentive being claimed.
Calculation
2 items
The base amount used to calculate the credit.
Calculated credit amount after applying formulas and limitations.
Certification
1 items
Detailed breakdown supporting the credit calculation.
Signatures
1 items
Sign and date the form.
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Fillable formOpen in Editor->The form is the 20/25 edition. For the latest developments, the instructions direct filers to IRS.gov/Form8959.
What changed or needs a fresh check
- Edition date — confirm the form shows the 20/25 revision as indicated in the instructions.
- Fee — not stated in the official source.
- Mailing address — not stated in the official source.
- Signature — not stated in the official source.
Quick Facts
Downloads
After you file
- 1Attach completed Form 8959 to Form 1040, Form 1040‑SR, Form 1040‑NR, or Form 1040‑SS before filing — source p.1.
- 2If correcting a liability, file a corrected Form 8959 with the original or amended return — source p.2.
- 3When correcting Medicare wages or RRTA compensation, also attach the original Form W‑2 or a Form W‑2c — source p.2.
- 4Keep the filed Form 8959 and all supporting W‑2 documents with your tax records for at least three years — general filing practice.
Sources
- SRCInstructions p.1 — purpose: Form 8959 figures the amount of Additional Medicare Tax you owe and the amount withheld.
- SRCInstructions p.1 — threshold amounts: Married filing jointly $250,000; Married filing separately $125,000; Single $200,000; Head of household $200,000; Qualifying surviving spouse $200,000.
- SRCInstructions p.1 — filing requirement: Must file Form 8959 if any single Form W‑2 box 5 exceeds $200,000 or box 14 exceeds $200,000.
- SRCInstructions p.1 — attach Form 8959 to Form 1040, Form 1040‑SR, Form 1040‑NR, or Form 1040‑SS.
- SRCInstructions p.2 — if you don’t owe Additional Medicare Tax, you can claim a credit for any withheld tax by filing Form 8959.
- SRCInstructions p.2 — correcting liability: attach a corrected Form 8959 to the original or amended return.
- SRCInstructions p.2 — when correcting wages or RRTA compensation, also attach Form W‑2 or Form W‑2c.
- SRCInstructions p.3 — line 13 calculation: multiply line 12 by 0.9% (0.009) to get Additional Medicare Tax on self‑employment income.
- SRCInstructions p.4 — joint return: include spouse’s Additional Medicare Tax withheld; line 24 amount goes to line 25c of Form 1040 or line 11a of Form 1040‑SS.
- SRCInstructions p.2 — no special rules for Additional Medicare Tax for nonresident aliens and U.S. citizens living abroad.
Common confusion points
Do I need to file Form 8959 if my employer already withheld Additional Medicare Tax?
The form is required to report the tax and claim any credit, even when tax was withheld.
→ Verify that line 24 on Form 8959 is entered on the appropriate line of your Form 1040 return.
What threshold applies to my filing status?
The instruction lists different dollar amounts for each filing status.
→ Check the filing‑status table on Instructions p.1 for the correct threshold.
Is self‑employment income taxed if I already have Medicare wages above the threshold?
The self‑employment threshold is reduced by the amount of Medicare wages, but not below zero.
→ Confirm the reduced threshold calculation on the worksheet in the instructions.
Do I include my spouse’s Additional Medicare Tax withheld on a joint return?
Joint returns must include spouse’s withheld tax per the instructions.
→ Ensure the amount from line 24 is entered on line 25c of Form 1040 (or line 11a of Form 1040‑SS).
Which box on Form W‑2 reports Medicare wages for this calculation?
Box 5 contains Medicare wages and tips; for Form 499R‑2/W‑2PR, box 22 is used.
→ Verify that box 5 (or box 22 for PR) exceeds $200,000 before filing.
What forms do I need to attach if I correct my wages after filing?
A corrected Form 8959 must be accompanied by a corrected wage statement.
→ Attach Form W‑2c (or the original Form W‑2) with the corrected Form 8959.
Workflow map
Related forms and next steps
Before
Current
After
Often used with
⚠ If something goes wrong
- Form W‑2c – corrected wage statement to attach when revising Medicare wages.
- Form CT‑2 – reports Additional Medicare Tax paid by employee representatives subject to RRTA taxes.
Questions about IRS Form 8959
What is IRS Form 8959 used for?
Form 8959 tells you how much extra Medicare tax you need to pay on high earnings. You add up wages, self‑employment earnings, and railroad compensation that go over $200,000, apply the 0.9% rate, and report the total with your tax return.
Who must file IRS Form 8959?
Taxpayers who owe Additional Medicare Tax or whose employer withheld it must file IRS Form 8959 with their Form 1040 series return.
What information does IRS Form 8959 require?
The form collects Medicare wages, self‑employment income, and RRTA compensation, calculates the 0.9% tax on each (Lines 7, 8, 17), and reconciles any tax already withheld (Line 19).
How do I complete IRS Form 8959?
Enter your name and Social Security number, then report Medicare wages in Part I and compute Line 7 by multiplying by 0.9%. Report self‑employment income in Part II (Line 8) and RRTA compensation in Part III (Line 14, then Line 17). Reconcile any Medicare tax withheld in Part V (Line 19) and attach the completed Form 8959 to your Form 1040 series return.
What happens if IRS Form 8959 is filed incorrectly?
If the tax is not paid timely, you may face an estimated‑tax penalty for waiting to pay the Additional Medicare Tax with your return.
Do I need to file Form 8959 if my employer already withheld Additional Medicare Tax?
The form is required to report the tax and claim any credit, even when tax was withheld. Verify that line 24 on Form 8959 is entered on the appropriate line of your Form 1040 return.
What threshold applies to my filing status?
The instruction lists different dollar amounts for each filing status. Check the filing‑status table on Instructions p.1 for the correct threshold.
Is self‑employment income taxed if I already have Medicare wages above the threshold?
The self‑employment threshold is reduced by the amount of Medicare wages, but not below zero. Confirm the reduced threshold calculation on the worksheet in the instructions.
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