Payroll taxes are the Social Security and Medicare taxes withheld from your paycheck, plus the employer portion you don't see

Payroll taxes fund two federal programs: Social Security and Medicare. When you work, your employer withholds a percentage of your gross pay for each. Your employer also pays a matching amount on your behalf — money that comes out of what they would otherwise pay you in wages. Together, these make up your payroll tax burden.

The withholding happens automatically. You see it on your pay stub as "FICA" (Federal Insurance Contributions Act) or sometimes broken into "Social Security" and "Medicare" line items. The employer portion is not shown on your paycheck, but it is a real cost to your employer and affects how much total compensation you receive.

Unlike income tax, payroll taxes have a wage cap. For Social Security, you stop paying once your earnings hit a threshold that changes each year. Medicare has no cap — you pay it on all wages. Self-employed people pay both the employee and employer portions themselves, which is why their tax bill is higher than a W-2 employee's for the same income.

Key Takeaways

  • Social Security tax is 6.2% of your wages (employee) plus 6.2% from your employer, up to an annual wage cap that changes yearly.
  • Medicare tax is 1.45% of all your wages (employee) plus 1.45% from your employer, with no wage limit.
  • High earners pay an additional 0.9% Medicare tax on wages above a threshold ($200,000 for single filers, $250,000 for married filing jointly).
  • Self-employed workers pay both the employee and employer share, totaling 15.3% for Social Security and Medicare combined on net earnings.
  • Payroll taxes fund your future Social Security benefits and Medicare coverage, not general government spending.

How Social Security tax works

Social Security tax is 6.2% of your wages, withheld from your paycheck. Your employer pays another 6.2%. The combined 12.4% funds the Social Security program, which provides retirement, disability, and survivor benefits.

The catch is the wage base limit. In 2024, you pay Social Security tax only on the first $168,600 of earnings. Once you hit that amount in a calendar year, no more Social Security tax is withheld from your remaining paychecks that year. If you change jobs mid-year, you might overpay — you can claim the excess as a credit on your tax return. The wage base changes annually based on average wage growth.

Your Social Security benefits later are tied to how much you paid in over your working years. The more you earn (up to the wage cap) and the longer you work, the higher your benefit. Payments begin at age 62 (reduced) or age 67 or later (full amount, depending on your birth year).

How Medicare tax works

Medicare tax is 1.45% of your wages, withheld from your paycheck, plus another 1.45% from your employer. Unlike Social Security, there is no wage cap — you pay Medicare tax on every dollar you earn, no matter how high your income.

At age 65, you become may be able to access for Medicare Part A (hospital insurance) and Part B (medical insurance). The payroll taxes you paid fund these programs. You can enroll in Medicare even if you do not yet receive Social Security benefits.

High earners face an additional Medicare tax. If you earn more than $200,000 (single), $250,000 (married filing jointly), or $125,000 (married filing separately), you pay an extra 0.9% Medicare tax on the amount above the threshold. This is withheld from your paycheck if you are a W-2 employee. Self-employed people calculate it on their tax return.

The self-employed payroll tax burden

If you are self-employed, you pay both the employee and employer share of payroll taxes. That means 12.4% for Social Security (up to the wage cap) and 2.9% for Medicare (no cap), totaling 15.3% before any additional Medicare tax.

You calculate this on Schedule SE (Self-Employment Tax) using your net business income. You can deduct half of your self-employment tax as an above-the-line deduction on your Form 1040, which lowers your taxable income. The other half is a business expense that reduces your net earnings subject to self-employment tax.

Self-employed people often owe estimated quarterly taxes because no employer is withholding on their behalf. You calculate what you expect to owe for the year and send in four equal payments to the IRS. Underpaying can result in penalties and interest.

Payroll taxes versus income tax

Payroll taxes and income tax are separate. Payroll taxes fund Social Security and Medicare specifically. Income tax funds general government operations. You pay both, and they appear as separate line items on your pay stub.

Payroll taxes have fixed rates (6.2% Social Security, 1.45% Medicare) and are not affected by your filing status, deductions, or credits. Income tax withholding, by contrast, depends on the W-4 form you file with your employer and changes based on your total tax situation.

When you file your annual tax return, you report both. Payroll taxes withheld appear on your W-2 (if you are an employee) or are calculated on Schedule SE (if you are self-employed). Income tax withheld also appears on your W-2. If you overpaid either one, you get a refund; if you underpaid, you owe.

Why the wage cap matters for high earners

The Social Security wage cap creates a significant difference in tax burden for high earners. Once you earn above the cap, you stop paying Social Security tax for the rest of that year. A person earning $200,000 pays Social Security tax on only the first $168,600 (in 2024), while someone earning $100,000 pays on all of it.

This means high earners pay a lower effective Social Security tax rate than middle-income workers. A person earning $168,600 pays the full 12.4% (employee and employer combined). A person earning $336,000 pays only 6.2% of their total income in Social Security tax.

Medicare tax has no such cap, so high earners pay the full 1.45% (plus the additional 0.9%) on all their wages. This is why Medicare is sometimes described as having a more progressive structure than Social Security for very high earners.

How payroll taxes appear on your pay stub

Your pay stub shows gross pay (before any deductions), then lists payroll tax withholdings. You will see lines for "Social Security" or "FICA-SS" and "Medicare" or "FICA-Med". These are the amounts withheld from your paycheck.

Your employer's matching portion does not appear on your pay stub because it is not deducted from your wages — it is a separate cost to the employer. However, it is reported to the IRS on your W-2 form in Box 12 (under code D for uncollected employee Social Security tax, if applicable, though this is rare).

At the end of the year, your W-2 shows total Social Security wages and total Medicare wages in separate boxes, along with the tax withheld. Self-employed people report this information on Schedule SE and Form 1040.

Frequently Asked Questions

Can I opt out of paying payroll taxes?

No. Payroll taxes are mandatory for all employees and self-employed people with net earnings above $400. Some religious groups have exemptions, but these require IRS approval and are rare. If you are an employee, your employer must withhold payroll taxes by law.

What happens if I overpay Social Security tax?

If you change jobs and both employers withheld Social Security tax after you hit the wage cap, you overpaid. You can claim the excess as a credit on your Form 1040 when you file your tax return. The IRS will refund the overpayment or explore it to other taxes owed.

Do payroll taxes count toward my income tax?

No. Payroll taxes and income tax are separate. However, payroll taxes withheld reduce the amount of income tax you owe, because they are a form of prepayment. If you overpay payroll taxes, you can use that credit against income tax owed, but the taxes themselves are distinct.

Why do I pay payroll taxes if I might not collect Social Security?

Payroll taxes fund not just retirement benefits but also disability and survivor benefits. Even if you die before retirement age, your family may receive survivor benefits. If you become disabled, you may receive benefits before age 62. The taxes you pay build credits toward these protections.

How do I know if I paid the right amount of payroll tax?

Check your W-2 at the end of the year. It shows your gross wages, Social Security wages, Medicare wages, and the tax withheld for each. Compare the withholding to the rates (6.2% for Social Security up to the cap, 1.45% for Medicare). If the amounts do not match, contact your employer or a tax professional.