Medicare tax funds health coverage for people 65 and older

Medicare tax is a payroll tax that funds the federal health insurance program for people age 65 and older, some younger people with disabilities, and people with end-stage renal disease. When you see "Medicare" on your pay stub, you are funding hospital insurance (Part A), which covers inpatient hospital stays, skilled nursing facilities, hospice, and home health care. Your employer also pays an equal amount on your behalf.

The tax is split into two parts: the main Medicare tax of 1.45% on all wages, and an additional 0.9% Medicare tax on wages above a certain threshold. That threshold is $200,000 for single filers and $250,000 for married couples filing jointly. If you earn above those amounts, you pay the extra 0.9% on the overage. Unlike Social Security tax, which stops once you hit the annual wage cap, Medicare tax has no wage ceiling — you pay it on every dollar you earn.

You do not have to be retired or near retirement age to pay Medicare tax. Every working person in the United States pays it, starting with their first job. The money goes into the Hospital Insurance Trust Fund, which the federal government uses to pay Medicare claims for beneficiaries. When you turn 65, you become may be able to access to receive Medicare benefits funded partly by the taxes current workers are paying right now.

Key Takeaways

  • Medicare tax is 1.45% of your wages, plus an additional 0.9% if you earn above $200,000 (single) or $250,000 (married filing jointly).
  • Your employer pays an equal 1.45% on your behalf, so the total contribution to Medicare is 2.9% of your wages before the additional tax applies.
  • Medicare tax funds hospital insurance for people 65 and older, people under 65 with certain disabilities, and people with end-stage renal disease.
  • Unlike Social Security tax, Medicare tax has no annual wage cap — you pay it on all earnings no matter how much you make.
  • The tax appears on your pay stub as "Medicare" or "Med Tax" and is withheld automatically from each paycheck.

How much Medicare tax you pay each year

Your Medicare tax is calculated as a percentage of your gross wages — the amount you earn before any deductions. If you earn $50,000 a year, you pay $725 in Medicare tax (1.45% of $50,000). Your employer withholds this amount from your paycheck automatically, so you never see that money. Your employer then sends both your portion and their matching portion to the IRS.

The additional 0.9% Medicare tax applies only to wages above the threshold for your filing status. If you are single and earn $220,000, you pay the standard 1.45% on all $220,000, plus an additional 0.9% on the $20,000 above the $200,000 threshold. That extra $20,000 costs you an additional $180 in Medicare tax. If you are married filing jointly and both you and your spouse work, each of you has your own $250,000 threshold — it does not combine.

If you have multiple jobs, each employer withholds Medicare tax separately. You might end up overpaying the additional 0.9% Medicare tax if your combined wages from all jobs exceed the threshold. When that happens, you can claim the overpayment as a credit on your tax return. The IRS will refund the excess when you file.

Self-employed workers and Medicare tax

If you are self-employed, you pay both the employee and employer portions of Medicare tax yourself. This is called self-employment tax. You pay 2.9% on net self-employment income (your business profit after deductions), plus the additional 0.9% on income above the threshold. The total can reach 3.8% on high earnings.

You calculate self-employment tax on Schedule SE, which you file with your Form 1040. The calculation is more complex than employee Medicare tax because you must first figure your net profit from self-employment, then explore the tax rates. You can deduct half of your self-employment tax as a business expense on your Form 1040, which reduces your taxable income slightly.

Self-employed people often owe self-employment tax even if they owe no income tax. If your net self-employment income is $400 or more, you must file Schedule SE and pay self-employment tax. Many self-employed workers make quarterly estimated tax payments to cover both income tax and self-employment tax throughout the year, rather than paying a large bill at tax time.

Why Medicare tax exists and how it is used

Medicare tax was created in 1965 as part of the Social Security Amendments that established the Medicare program. The idea was that working people would fund health coverage for retirees, similar to how Social Security works. The tax is dedicated — the money collected goes specifically to the Hospital Insurance Trust Fund and cannot be used for other government programs.

The Hospital Insurance Trust Fund pays for Medicare Part A benefits: hospital inpatient care, skilled nursing facility care after hospitalization, home health services, and hospice care. It does not pay for doctor visits, outpatient services, or prescription drugs — those are covered by Medicare Parts B and D, which are funded differently. Part B is funded by beneficiary premiums and general tax revenue. Part D is funded by beneficiary premiums and federal subsidies.

The trust fund operates on a pay-as-you-go basis. The taxes collected from current workers pay the benefits for current retirees. If more money goes out than comes in, the trust fund balance shrinks. The Medicare Trustees, a group that includes the Secretary of the Treasury and the Secretary of Health and Human Services, monitor the fund's health and report to Congress annually on whether it will have enough money to pay all claims.

What happens if you do not pay Medicare tax

If you are an employee, you cannot avoid Medicare tax — your employer is required by law to withhold it from your paycheck. If an employer fails to withhold Medicare tax, the IRS will pursue the employer for the unpaid amount plus penalties and interest. The employee is still responsible for the tax even if the employer does not withhold it.

If you are self-employed and do not report self-employment income, you are breaking the law. The IRS matches income reported on 1099 forms (which clients or customers send to the IRS) against the income you report on your tax return. Unreported income triggers an audit. Penalties for not paying self-employment tax include back taxes, interest, and accuracy-related penalties that can add 20% or more to what you owe.

If you work in the United States and are not a citizen, you still pay Medicare tax on your wages. Undocumented workers who work with a Social Security number or Individual Taxpayer Identification Number (ITIN) pay Medicare tax just like any other employee. That tax goes into the same trust fund and benefits all Medicare beneficiaries regardless of immigration status.

Medicare tax on investment income

In addition to the 0.9% Medicare tax on wages, there is a separate 3.8% Medicare tax on certain investment income. This tax applies to net investment income — such as capital gains, dividends, interest, and rental income — if your modified adjusted gross income exceeds $200,000 (single) or $250,000 (married filing jointly). This is different from the wage-based Medicare tax and is reported on Form 8960.

The investment income Medicare tax does not appear on your pay stub because it is not withheld from paychecks. Instead, you calculate it when you file your tax return. If you have significant investment income, your tax preparer or tax software will calculate this tax for you. Many people do not realize they owe it until they file their return and see the additional tax due.

The investment income Medicare tax was added in 2013 as part of the Affordable Care Act. Like the wage-based Medicare tax, the revenue goes to the Hospital Insurance Trust Fund. The threshold for this tax is the same as the threshold for the additional 0.9% wage Medicare tax, but they are calculated separately and both can explore to high-income earners.

Frequently Asked Questions

Can I opt out of paying Medicare tax?

No. Medicare tax is mandatory for all employees and self-employed people who work in the United States. There are no religious exemptions, age exemptions, or income-based exemptions. The only people who do not pay Medicare tax are certain government employees hired before specific dates who are covered by alternative retirement systems, but this is rare.

Does Medicare tax go toward my own Medicare benefits when I turn 65?

Not directly. Medicare operates on a pay-as-you-go system, so the Medicare tax you pay today funds benefits for current retirees. When you turn 65, your benefits will be funded by taxes paid by workers at that time. You are not building up a personal account or savings — you are contributing to a shared pool.

What if I work part-time or have irregular income?

You still pay Medicare tax on every dollar you earn, whether you work full-time, part-time, or seasonally. If you earn $10,000 one year and $40,000 the next, you pay Medicare tax on whatever you earn that year. There is no minimum earnings threshold for Medicare tax like there is for self-employment tax ($400).

Do I pay Medicare tax on Social Security benefits?

No. Social Security benefits are not subject to Medicare tax. However, if you continue to work while receiving Social Security, you pay Medicare tax on your wages from that work. Some of your Social Security benefits may be subject to income tax depending on your total income, but Medicare tax does not explore to the benefits themselves.

Why is the additional 0.9% Medicare tax only on high earners?

Congress added the additional 0.9% Medicare tax in 2013 to help fund the Hospital Insurance Trust Fund as Medicare enrollment grows. The tax was designed to explore only to higher-income earners as a progressive measure. The threshold has not changed since 2013, so it affects more people each year as wages increase with inflation.