What you pay into Social Security and Medicare while working

While you are working, your employer takes money from your paycheck for two separate taxes: one for Social Security and one for Medicare. These are payroll taxes, and they appear on your pay stub as FICA (Federal Insurance Contributions Act). Your employer also contributes an equal amount on your behalf — you do not see that money, but it counts toward your benefits.

For Social Security, you pay 6.2% of your wages, up to a yearly cap. The cap changes each year — in 2024 it was $168,600, meaning once you earn that much in a calendar year, no more Social Security tax comes out. For Medicare, you pay 1.45% of all your wages with no cap. If you earn over $200,000 as a single filer (or $250,000 married filing jointly), an additional 0.9% Medicare tax applies to the amount above that threshold.

Self-employed people pay both the employee and employer share — 12.4% for Social Security (with the same yearly cap) and 2.9% for Medicare (no cap), plus the extra 0.9% if income exceeds the threshold. You can deduct half of your self-employment tax when you file your income tax return.

Key Takeaways

  • Social Security tax is 6.2% of your wages up to an annual cap that changes yearly; Medicare tax is 1.45% of all wages with no cap.
  • Your employer pays an equal amount into Social Security and Medicare on your behalf, though you do not see it on your paycheck.
  • High earners pay an additional 0.9% Medicare tax on income above $200,000 (single) or $250,000 (married filing jointly).
  • Self-employed workers pay both the employee and employer share of these taxes, totaling 15.3% for Social Security and Medicare combined.
  • The money you pay in now funds current retirees' benefits; your own benefits later are based on your earnings record, not the amount you paid in.

Why there is a Social Security wage cap but not a Medicare cap

Social Security has a yearly earnings cap because the program was designed to replace a portion of your working income, not all of it. The idea is that higher earners do not need the same income replacement percentage as lower earners. Once you hit the cap in a given year, no more Social Security tax comes out, even if you earn significantly more.

Medicare has no cap because it is structured as insurance for medical costs in retirement, not as an income-replacement program. The more you earn over your lifetime, the more you are expected to contribute to the pool that covers everyone's hospital and medical bills at 65 and older.

How these taxes affect your take-home pay

Together, Social Security and Medicare taxes reduce your paycheck by 7.65% (6.2% + 1.45%), assuming you are below the high-earner threshold. If you earn over the income thresholds for the extra Medicare tax, that percentage goes up slightly. For someone earning $50,000 a year, that is roughly $3,825 in combined payroll taxes before income tax is withheld.

These taxes are separate from federal income tax, state income tax, and local taxes. Your employer withholds all of them from your paycheck. When you file your tax return each year, you cannot reduce your taxable income by the amount you paid in Social Security and Medicare taxes — those are already deducted from your gross pay before income tax is calculated.

What happens to the money you pay in

The Social Security and Medicare taxes you pay do not go into a personal account with your name on it. Instead, they go into a trust fund that pays benefits to current retirees, disabled workers, and their families (Social Security) and to people 65 and older and some younger people with disabilities (Medicare). Your own benefits later are based on your earnings record — the amount you earned in covered employment — not the amount you paid in taxes.

This is why your Social Security statement shows your estimated future benefit based on your earnings history, not on a calculation of what you put in. If you earned very little in some years, those years still count, which can lower your average. If you stop working early, your benefit is lower than if you worked longer, even if you paid the same total amount in taxes.

Tax treatment of Social Security benefits in retirement

Once you start receiving Social Security benefits, part of those benefits may be subject to federal income tax, depending on your total income in retirement. This is different from the payroll taxes you paid while working. The IRS uses a formula based on your "combined income" — your adjusted gross income plus nontaxable interest plus half your Social Security benefits — to determine whether your benefits are taxed.

If your combined income is below $25,000 (single) or $32,000 (married filing jointly), your Social Security benefits are not taxed. Above those thresholds, up to 50% of your benefits may be taxable, and above higher thresholds, up to 85% may be taxable. Some states also tax Social Security benefits, though many do not. You can ask the Social Security Administration to withhold federal income tax from your benefit payments if you want to avoid a tax bill at the end of the year.

Medicare premiums and taxes are not the same thing

The 1.45% Medicare tax you pay while working funds Part A (hospital insurance). Once you turn 65 and enroll in Medicare, you pay separate premiums for the coverage you choose — Part B (medical insurance), Part D (prescription drugs), and possibly supplemental or Part C (Medicare Advantage) plans. These premiums are not taxes; they are monthly charges for your coverage.

Higher-income retirees also pay an additional amount called an Income-Related Monthly Adjustment Amount (IRMAA) on top of their Part B and Part D premiums. This is based on your income from two years prior and is separate from both the payroll tax you paid while working and your regular premiums. Understanding the difference helps you plan for the actual costs you will face in retirement.

How to read your pay stub and verify your earnings record

Your pay stub shows the gross amount you earned, then lists deductions. Look for "FICA-SS" or "Social Security" (6.2% of gross, up to the yearly cap) and "FICA-Medicare" or "Medicare" (1.45% of gross). If you earn over the high-income threshold, you will also see "Additional Medicare Tax" or "Medicare Tax 0.9%". Your employer's contribution does not appear on your pay stub.

Once a year, you can check your earnings record on your Social Security account at ssa.gov. Create a "my Social Security" account to see your estimated benefits, your earnings history, and the amount of Social Security and Medicare taxes you have paid. If you spot an error — a missing year, an incorrect amount, or a name mismatch — report it to Social Security as soon as possible, because errors can affect your future benefits.

Frequently Asked Questions

Do I pay Social Security and Medicare taxes on all my income?

Social Security tax applies only to wages up to the yearly cap (which changes annually). Medicare tax applies to all wages with no cap. If you are self-employed, both taxes explore to your net self-employment income after you subtract half your self-employment tax.

Can I opt out of paying Social Security and Medicare taxes?

No. These are mandatory payroll taxes for all workers in the United States, with very few exceptions (some government employees hired before 1984 and certain religious groups). If you are employed, your employer must withhold them.

What if I worked in another country — do those years count toward my Social Security benefit?

It depends on whether the country has a totalization agreement with the United States. Some countries do; others do not. Contact Social Security or visit ssa.gov/international to learn whether your work abroad counts toward your U.S. benefit.

If I delay claiming Social Security, do I pay less in taxes on my benefits later?

Delaying does not change the payroll taxes you paid while working. However, your benefit amount will be higher when you do claim, which may affect how much of your benefit is taxed as income in retirement. The income-tax calculation depends on your total retirement income, not on when you claimed.

Why do I pay Medicare tax if I will have to pay premiums anyway?

The 1.45% payroll tax funds Part A (hospital insurance), which is free at 65 if you paid Medicare taxes for at least 10 years. Part B and Part D premiums are separate charges for additional coverage. Together, the tax and premiums spread the cost of Medicare across workers and retirees.