Medicare tax funds the health coverage you'll use in retirement
You pay Medicare tax now so that when you turn 65, the program will cover hospital stays, doctor visits, and other medical care. The money you and your employer contribute over your working years goes into a trust fund that pays benefits for current retirees — and later, your own benefits will be paid by workers who come after you. It's a system where each generation funds the one ahead of them.
The tax appears on your paycheck as two separate lines: 1.45% for Hospital Insurance (Part A) and 1.45% for Supplementary Medical Insurance (Part B), for a total of 2.9%. Your employer matches that amount, so the total contribution is 5.8% of your wages. If you're self-employed, you pay both sides yourself — 2.9% of your net earnings.
Unlike Social Security tax, which stops after you earn a certain amount each year, Medicare tax has no income cap. You pay it on every dollar you earn, no matter how much you make.
Key Takeaways
- Medicare tax funds hospital insurance and medical insurance for people 65 and older, paid for by current workers' contributions.
- You pay 1.45% and your employer pays 1.45% of your wages, with no upper income limit on what gets taxed.
- The money goes into two trust funds: one for hospital care and one for doctor and outpatient services.
- Higher earners pay an additional 0.9% Medicare tax on income above $200,000 (single) or $250,000 (married filing jointly).
How the two Medicare trust funds work
Your Medicare tax contributions are split between two separate accounts. The Hospital Insurance Trust Fund (Part A) pays for inpatient hospital care, skilled nursing facilities, hospice, and home health services. The Supplementary Medical Insurance Trust Fund (Part B) covers doctor visits, outpatient services, lab work, and medical equipment.
Both funds operate on a pay-as-you-go basis. The taxes collected this year pay the benefits going out this year to current retirees. The funds are managed by the Centers for Medicare & Medicaid Services (CMS), a federal agency under the Department of Health and Human Services. Each fund publishes an annual report showing how much money came in, how much went out, and whether the fund is projected to have enough money in future years.
The Hospital Insurance Trust Fund has faced periods where projected spending exceeded projected income, which is why you may have heard concerns about Medicare's long-term solvency. Congress can adjust tax rates, benefits, or may be able to access rules to keep the funds balanced, but those decisions require legislation.
The additional Medicare tax on high earners
If you earn above a certain threshold, you pay an extra 0.9% Medicare tax on the income that exceeds it. For single filers, the threshold is $200,000 per year. For married couples filing jointly, it's $250,000. For married people filing separately, it's $125,000. This additional tax has been in place since 2013.
Your employer withholds this extra tax automatically if your wages cross the threshold. If you have multiple jobs or other income sources, you may need to account for it when you file your tax return, because each employer withholds based only on what they pay you — not your total income from all sources.
Why Medicare tax exists and what it replaced
Before Medicare began in 1965, most people over 65 had no health insurance. Many went without care because they couldn't afford it, or they relied on their adult children or charity. Medicare tax was created as a way to spread the cost of health care for older adults across the entire working population, so no single generation or family bore the full burden.
The program was designed to be self-financing through payroll taxes, similar to Social Security. The idea was that workers would contribute during their earning years and receive benefits after retirement. This approach meant the program didn't require annual appropriations from Congress — it had its own dedicated funding stream.
Over time, medical costs have risen faster than wages, which is why the program has required adjustments. The additional 0.9% tax on high earners was added as one way to help shore up the funds without raising the base tax rate on all workers.
What happens to Medicare tax money you pay
When you pay Medicare tax, the money doesn't sit in an account with your name on it. Instead, it goes into the general trust funds, and benefits are paid out based on need and may be able to access, not on how much any individual contributed. This is different from a private pension or retirement savings account.
Right now, the money collected in Medicare taxes is enough to pay current benefits, though the Hospital Insurance Trust Fund's reserves have fluctuated. The trustees of both funds publish projections about when reserves might be depleted if no changes are made. These reports are public and available on the CMS website, so you can see the actual numbers rather than relying on news headlines.
If you move to another country or work abroad, you may still owe Medicare tax on U.S. wages, depending on your visa status and the tax treaty between the U.S. and that country. Self-employed people abroad may have different rules. A tax professional or the IRS can clarify your specific situation.
How Medicare tax differs from other payroll taxes
Social Security tax and Medicare tax are often grouped together on your paycheck, but they fund different programs and have different rules. Social Security tax is 6.2% (employer matches 6.2%), and it only applies to the first $168,600 of your wages in 2024 — that cap changes each year. Once you earn above that amount, you stop paying Social Security tax for the rest of the year.
Medicare tax, by contrast, has no wage cap. You pay 1.45% on every dollar you earn, no matter how much that is. This means higher earners pay more Medicare tax in absolute dollars, even though the rate is lower than Social Security tax. The additional 0.9% tax on high earners makes the total Medicare tax rate 2.35% for those above the threshold, compared to 2.9% for everyone else.
Both taxes fund programs that are legally separate, have their own trust funds, and operate under different rules for who receives benefits and when.
Frequently Asked Questions
Can I opt out of paying Medicare tax?
No. Medicare tax is mandatory for all employees and self-employed people in the United States. Some religious groups have exemptions from Social Security tax, but those exemptions do not extend to Medicare tax. If you're self-employed, you must pay both the employee and employer portions of Medicare tax on your net earnings from self-employment.
What if I never worked long enough to pay Medicare tax?
You can still enroll in Medicare at 65 even if you have no work history or paid very little Medicare tax. However, you may have to pay a higher premium for Part B (doctor and outpatient coverage) if you didn't have coverage for at least 30 months. The premium surcharge is 10% for each 12-month period you were may be able to access but didn't enroll.
Do I get Medicare automatically when I turn 65?
No. You must enroll during your Initial Enrollment Period, which is the three months before, the month of, and the three months after your 65th birthday. If you delay enrollment without good reason, you may face late-enrollment penalties on your premiums. If you're still working and covered by your employer's health plan, you may be able to delay enrollment without penalty — check with your employer's benefits office.
Does Medicare tax pay for all of my medical care in retirement?
Medicare covers hospital care, doctor visits, and some preventive services, but it does not cover everything. You'll still have copayments, coinsurance, and deductibles. Long-term care, dental, vision, and hearing are generally not covered. Many people buy supplemental insurance or enroll in Medicare Advantage plans to fill those gaps.
What happens to my Medicare tax if I die before I turn 65?
The money you paid in Medicare tax goes into the general trust fund and is used to pay benefits for current retirees. Unlike Social Security, Medicare does not pay survivor benefits to your family based on your work record. Your contributions support the program for everyone, not a personal account that passes to your heirs.