6 — Medicare Tax Withheld Updated for tax year 2025

What this line means

The total Medicare tax your employer withheld from your paychecks during the year. The base rate is 1.45% of all your Medicare wages (Box 5). If your wages from this employer exceeded $200,000, your employer also withheld the 0.9% Additional Medicare Tax on the amount above that threshold — both portions are combined in Box 6.

Does this apply to you?

• You earned wages and your employer withheld Medicare tax from every paycheck
• You want to verify that Box 6 equals at least 1.45% of Box 5
• You earned over $200,000 from one employer and see Box 6 is higher than 1.45% of Box 5
• You are filing Form 8959 to calculate whether you owe additional Medicare tax

Easy to overlook

The Additional Medicare Tax may not be fully withheld Your employer starts withholding the extra 0.9% once your wages from that job pass $200,000. But if you are married filing jointly, the threshold is $250,000 of combined household wages. If you earned $180,000 and your spouse earned $120,000, neither employer withheld the additional tax — but your combined $300,000 exceeds the MFJ threshold by $50,000. You owe 0.9% on that $50,000 when you file. ¹ [SOURCE: IRS Form 8959 — Additional Medicare Tax]

Your employer pays a matching 1.45% you never see Just like Social Security tax, your employer pays 1.45% on top of your 1.45%. The employer portion does not appear on your W-2. Combined, Medicare tax is 2.9% of wages (plus the 0.9% additional tax on high earners, which the employer does not match). ² [SOURCE: SSA — 2025 Medicare rate 1.45% employee / 1.45% employer]

Watch out for this

Not filing Form 8959 when required. If your total Medicare wages across all W-2s exceed $200,000 (single), $250,000 (MFJ), or $125,000 (married filing separately), you must file Form 8959 to reconcile the Additional Medicare Tax. The form calculates whether your employer withheld enough. Skipping it when you owe additional tax triggers an IRS notice.

Related lines on your return

• Box 5 — Form W-2 — Medicare wages this tax was calculated on (Box 6 should be at least 1.45% of Box 5)
• Box 4 — Form W-2 — Social Security tax withheld; a separate payroll tax with a different rate and a wage cap
• Form 8959 — Additional Medicare Tax — Required if wages exceed $200,000 (single), $250,000 (MFJ), or $125,000 (MFS)