Payroll taxes are the money your employer withholds from your paycheck for Social Security, Medicare, and federal income tax

When you see your paycheck, the amount you take home is less than your gross pay. The difference is payroll taxes — money your employer removes before you receive it and sends to the federal government. These taxes fund three separate programs: Social Security, which provides retirement and disability benefits; Medicare, which covers hospital and medical insurance for people 65 and older; and federal income tax, which funds general government operations.

Your employer also pays payroll taxes on your behalf, matching a portion of what comes out of your check. This employer contribution does not appear on your paycheck, but it is part of your total payroll tax burden. Self-employed people pay both the employee and employer portions themselves.

Key Takeaways

  • Social Security and Medicare taxes are fixed percentages of your wages, while federal income tax withholding depends on your W-4 form and how much you earn.
  • Your employer withholds these taxes from each paycheck and sends them to the IRS; you see the deductions listed separately on your pay stub.
  • Social Security tax stops once you reach the annual wage cap, but Medicare tax continues on all earnings above that point.
  • The amount withheld for federal income tax is an estimate; you may owe more or receive a refund when you file your tax return.

How Social Security and Medicare taxes work

Social Security and Medicare are FICA taxes — the acronym stands for Federal Insurance Contributions Act. Your employer withholds 6.2 percent of your wages for Social Security and 1.45 percent for Medicare. These percentages are set by law and do not change based on your income or filing status.

Social Security tax has an annual wage cap. In 2024, you pay Social Security tax only on earnings up to $168,600. Once you reach that amount in a calendar year, your employer stops withholding Social Security tax from the rest of your paychecks that year. Medicare tax has no cap — you pay 1.45 percent on all your wages, no matter how much you earn. If your income exceeds $200,000 as a single filer (or $250,000 married filing jointly), you pay an additional 0.9 percent Medicare tax on the amount above that threshold.

Both Social Security and Medicare taxes appear as separate line items on your pay stub. The money goes into trust funds managed by the Social Security Administration and Centers for Medicare and Medicaid Services, not into a general government account.

How federal income tax withholding works

Federal income tax withholding is different from Social Security and Medicare because the rate is not fixed. Your employer uses the W-4 form you completed when you started your job to calculate how much to withhold from each paycheck. The W-4 asks about your filing status, number of dependents, other income, and whether you want extra money withheld.

The IRS provides tables that employers use to convert this information into a withholding amount. If you claim zero dependents and no adjustments, your employer withholds more; if you claim dependents or request less withholding, your employer withholds less. The goal is to withhold roughly the amount of federal income tax you will owe when you file your return in April.

Federal income tax withholding is an estimate. If your employer withholds too much, you receive a refund when you file your tax return. If your employer withholds too little, you owe money. You can adjust your withholding at any time by submitting a new W-4 to your employer.

What happens to payroll taxes after they are withheld

Your employer is required to send all withheld payroll taxes to the IRS on a set schedule — usually monthly, though large employers may send them more frequently. The employer also sends their matching portion of Social Security and Medicare taxes at the same time. The IRS then deposits the money into the appropriate trust funds or the general Treasury account.

You receive a record of all payroll taxes withheld on your W-2 form, which your employer sends you by January 31 each year. The W-2 shows your gross wages, the amount withheld for federal income tax, Social Security wages and tax, and Medicare wages and tax. You use this information when you file your federal income tax return.

Payroll taxes versus income tax: what is the difference

Federal income tax and payroll taxes are both withheld from your paycheck, but they fund different things and work differently. Federal income tax is progressive, meaning the rate increases as your income increases. It funds general government operations like defense, infrastructure, and federal agencies. The amount withheld depends on your W-4 and is an estimate.

Payroll taxes — Social Security and Medicare — are flat percentages that do not change based on income. They fund specific programs that you may draw from later: Social Security retirement or disability benefits, and Medicare hospital and medical coverage. These taxes are not an estimate; the amount you owe is fixed by law.

Self-employed payroll taxes

If you are self-employed, you pay both the employee and employer portions of Social Security and Medicare taxes yourself. This is called self-employment tax. You pay 12.4 percent for Social Security (up to the annual wage cap) and 2.9 percent for Medicare, plus the additional 0.9 percent Medicare tax if your net earnings exceed the income thresholds.

You calculate self-employment tax on Schedule SE, which you file with your federal income tax return. You can deduct half of your self-employment tax as a business expense on your tax return, which reduces your taxable income. Self-employed people must make estimated tax payments quarterly to the IRS if they expect to owe $1,000 or more in federal income tax and self-employment tax combined.

Reading your pay stub: where to find payroll taxes

Your pay stub breaks down payroll taxes into separate line items so you can see exactly where your money goes. Look for lines labeled "Social Security Tax" or "FICA-SS," "Medicare Tax" or "FICA-Med," and "Federal Income Tax Withholding" or "FIT." Each line shows the amount withheld from that paycheck.

Some pay stubs also show year-to-date totals, which add up all the taxes withheld since January 1. This helps you track whether you are approaching the Social Security wage cap or the Medicare threshold for additional tax. If you do not understand a line item on your pay stub, ask your payroll department or human resources office — they can explain what each deduction is for.

Frequently Asked Questions

Why do I pay Social Security tax if I might not collect it?

Social Security tax funds current retirees and disabled workers, not just your own future benefits. The program operates on a pay-as-you-go basis: current workers fund current beneficiaries. You build a record of earnings that determines your benefit amount if you retire, become disabled, or if your family receives survivor benefits after your death.

Can I opt out of payroll taxes?

No. Payroll taxes are mandatory for all employees and self-employed people. The only exception is certain members of religious groups that have received an IRS exemption, which requires a formal process and approval. If you are a W-2 employee, you cannot reduce or eliminate payroll tax withholding.

What if my employer does not withhold payroll taxes?

Your employer is legally required to withhold and send payroll taxes to the IRS. If your employer fails to do this, you are still responsible for the taxes owed. You can report non-compliance to the IRS using Form 13909 or contact the Department of Labor. Keep copies of your pay stubs as proof of wages earned.

Do payroll taxes change every year?

Social Security and Medicare tax rates stay the same, but the Social Security wage cap increases most years based on inflation. In 2024 it was $168,600; in 2025 it is $176,100. Federal income tax withholding can change if you submit a new W-4 or if tax law changes, which happens occasionally.