Medicare wages are the portion of your pay that your employer subjects to the 1.45% Medicare payroll tax, and for most workers that means almost everything on the paycheck. Unlike Social Security wages, which stop being taxed above an annual cap ($184,500 in 2026), Medicare wages have no ceiling. Every dollar of qualifying compensation gets taxed, no matter how much you earn.1Social Security Administration. Contribution and Benefit Base Knowing what falls in and what stays out is what lets you check Box 5 on your W-2, catch payroll errors, and avoid surprises at tax time.
What Counts as Medicare Wages
Federal law defines wages for Medicare purposes as all pay for employment, including the cash value of anything you’re paid in something other than cash.2Office of the Law Revision Counsel. 26 USC 3121 – Definitions That broad definition sweeps in most of what your employer gives you in exchange for your work:
- Regular pay: hourly wages, salaries, vacation pay, and sick pay.
- Supplemental pay: bonuses, commissions, and overtime.
- Tips, both cash and non-cash, that you report to your employer.
- Taxable fringe benefits such as personal use of a company car or employer-provided housing that has a measurable fair market value.
All of these are subject to Medicare withholding under IRS rules.3Internal Revenue Service. Publication 15 (2026), (Circular E), Employers Tax Guide
One item trips people up: 401(k) and 403(b) contributions. Those deferrals reduce your federal income tax, but they do not reduce your Medicare wages. The statute specifically keeps them in the Medicare tax base.4Office of the Law Revision Counsel. 26 USC 3121 – Definitions – Section: Treatment of Certain Deferred Compensation This is the main reason Box 5 (Medicare wages) is usually higher than Box 1 (federal taxable wages) on your W-2.
Employer-provided group-term life insurance also becomes part of your Medicare wages, but only when coverage exceeds $50,000. Below that threshold, the premiums are tax-free. Above it, the imputed cost of the excess coverage gets added to your Medicare wages.5Internal Revenue Service. Group-Term Life Insurance
What’s Excluded from Medicare Wages
A few specific types of compensation reduce your Medicare tax base. The most common are pre-tax deductions through a Section 125 cafeteria plan. When you elect to pay health insurance premiums, fund a flexible spending account, or fund a dependent care account through salary reduction under one of these plans, those amounts come out before Medicare tax is calculated.6Internal Revenue Service. FAQs for Government Entities Regarding Cafeteria Plans
Employer contributions to a Health Savings Account follow the same logic. Whether your employer makes the contribution directly or you fund it through payroll deduction under a cafeteria plan, those dollars are generally exempt from Medicare tax.7Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans
Several fringe benefits stay out of your Medicare wages as long as they fall within IRS limits for 2026:
- Qualified transportation benefits: up to $340 per month for transit passes or commuter van rides, plus up to $340 per month for qualified parking.
- Dependent care assistance: up to $7,500 per year ($3,750 if married filing separately).
- Accident and health plan coverage: employer-paid health insurance premiums are fully exempt.
Anything above those caps gets added back into your Medicare wages.8Internal Revenue Service. Publication 15-B (2026), Employers Tax Guide to Fringe Benefits
Business expense reimbursements are another exclusion, but only when your employer uses an accountable plan. That means you substantiate actual business expenses, return any excess payment, and the expenses have a genuine business connection. Reimbursements that fail any of those requirements become taxable wages subject to Medicare withholding.
How Medicare Wages Differ from Social Security Wages
The single biggest difference is the cap. Social Security tax applies only up to the annual wage base, $184,500 for 2026.1Social Security Administration. Contribution and Benefit Base Once your earnings cross that line, your employer stops withholding the 6.2% Social Security tax. Medicare wages have no equivalent limit. Every dollar of qualifying pay gets taxed for the entire year, no matter how large your salary.9Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
A concrete example from the IRS’s own W-2 instructions: if you earn $199,750 in 2026, Box 3 (Social Security wages) shows $184,500, but Box 5 (Medicare wages) shows the full $199,750. That $15,250 gap represents earnings taxed only for Medicare. The higher your income, the wider that gap becomes.
Retirement contributions add another wrinkle. Traditional 401(k) deferrals reduce Box 1 and Box 3 (up to the cap), but they do not reduce Box 5. Anyone contributing to a 401(k) will see Box 5 exceed Box 1, even at incomes well below the Social Security cap.
Medicare Tax Rates
The standard Medicare tax rate is 1.45% for the employee and 1.45% for the employer, totaling 2.9% on every dollar of Medicare wages.10Office of the Law Revision Counsel. 26 US Code 3101 – Rate of Tax The rate is fixed by statute and has held steady for years.
Additional Medicare Tax for Higher Earners
An extra 0.9% Medicare tax kicks in once your wages exceed a threshold that depends on your filing status:11Internal Revenue Service. Questions and Answers for the Additional Medicare Tax
- Single, head of household, or qualifying surviving spouse: $200,000.
- Married filing jointly: $250,000 (combined wages of both spouses).
- Married filing separately: $125,000.
These thresholds are set by statute and are not adjusted for inflation. They’ve been the same since the Additional Medicare Tax took effect in 2013. Above the threshold, your employee-side rate becomes 2.35% (1.45% plus 0.9%). The employer rate stays at 1.45% regardless of how much you earn.10Office of the Law Revision Counsel. 26 US Code 3101 – Rate of Tax
Why Withholding Doesn’t Always Match What You Owe
Your employer must start withholding the extra 0.9% in the pay period when your year-to-date wages pass $200,000, regardless of your filing status.12Internal Revenue Service. Topic no. 560, Additional Medicare Tax That single trigger produces two common mismatches for married couples. If you file jointly and both spouses earn under $200,000, neither employer withholds the extra tax, even if your combined income exceeds $250,000; you’ll owe the difference at filing. Going the other direction, if one spouse earns $220,000 but the combined household stays under $250,000, the employer over-withholds. Either way, you reconcile the actual amount on Form 8959 with your return, and any excess withholding is credited against your total tax.13Internal Revenue Service. 2025 Instructions for Form 8959
If You’re Self-Employed
When you work for yourself, you pay both halves of the Medicare tax, for a combined rate of 2.9% on net self-employment earnings.14GovInfo. 26 USC 1401 – Rate of Tax The same 0.9% Additional Medicare Tax applies above the filing-status thresholds. If you have both W-2 wages and self-employment income, the wages count first toward the threshold, and the Additional Medicare Tax applies to whatever combined amount exceeds it.
The tax base isn’t your gross revenue. You first subtract ordinary business expenses to get net profit, then multiply that net profit by 92.35% to get the amount actually subject to self-employment tax.15Internal Revenue Service. Topic no. 554, Self-Employment Tax The 7.65% reduction mirrors the fact that employees don’t pay FICA on the employer’s share.
Who Is Exempt from Medicare Tax
Most workers cannot opt out. A handful of narrow exemptions do exist.
Students enrolled at least half-time at a college or university, working for that same institution in a job incidental to their education, can be exempt. The exemption is lost if you’re eligible for benefits like a retirement plan, vacation pay, or reduced tuition beyond what’s offered to graduate teaching and research assistants.16Internal Revenue Service. Student FICA Exception
Foreign students and exchange visitors on F-1, J-1, or M-1 visas who have been in the United States for fewer than five calendar years are generally exempt from Medicare tax on wages earned for work their visa allows. After five calendar years, you typically become a resident alien for tax purposes and the exemption ends.17Internal Revenue Service. Foreign Student Liability for Social Security and Medicare Taxes
Members of recognized religious groups that have existed continuously since December 31, 1950, and are conscientiously opposed to accepting insurance benefits can apply using IRS Form 4029. Approval requires waiving all rights to Social Security and Medicare benefits permanently.18Internal Revenue Service. Form 4029, Application for Exemption From Social Security and Medicare Taxes and Waiver of Benefits
A very narrow grandfather clause covers state and local government employees hired before April 1, 1986, who have worked continuously for the same employer since then and were not covered by a Section 218 agreement with Social Security. Government workers hired after that date are subject to Medicare tax.
Finding Medicare Wages on Your W-2
Your total Medicare wages for the year appear in Box 5, labeled “Medicare wages and tips.” The Medicare tax withheld shows up in Box 6. Compare Box 5 to Box 1 (federal taxable wages) and Box 3 (Social Security wages). Box 5 will usually exceed Box 1 because 401(k) contributions are included, and it will match or exceed Box 3 because there’s no wage cap.9Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
If the Box 5 figure looks wrong, start with your employer’s payroll department. Common errors include miscoding a cafeteria plan deduction as post-tax, which inflates Medicare wages, or accidentally excluding reported tips. When an employer confirms a mistake, they file a corrected Form W-2c showing both the previously reported amount and the correct figure.19Internal Revenue Service. Form W-2c Corrected Wage and Tax Statement If the correction changes your Additional Medicare Tax liability, attach a corrected Form 8959 to your amended return.