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

When you see your paycheck, the amount you take home is less than what you earned. The difference is payroll tax — money your employer removes and sends to the government on your behalf. These withholdings cover three separate things: federal income tax, Social Security tax, and Medicare tax. Your employer also pays a matching amount for Social Security and Medicare that does not come from your check.

The amount withheld depends on what you told your employer on Form W-4 when you started the job, your income level, and your filing status. You are not losing money permanently — these are prepayments toward taxes you will owe when you file your return in April. If too much was withheld, you get a refund. If too little was withheld, you owe more.

Key Takeaways

  • Federal income tax, Social Security tax (6.2%), and Medicare tax (1.45%) all come out of your paycheck, with your employer matching the Social Security and Medicare portions.
  • The amount of federal income tax withheld is based on the W-4 form you completed when hired, which estimates your annual tax liability.
  • Self-employed people pay both the employee and employer portions of Social Security and Medicare, totaling 15.3% of net earnings.
  • You can adjust your withholding by submitting a new W-4 to your employer if you expect a large refund or owe money each year.

Federal Income Tax Withholding

Federal income tax is withheld based on the W-4 form you fill out when you start a job. This form asks for your filing status (single, married, head of household), the number of dependents you claim, and any additional income or deductions. Your employer uses this information to calculate how much federal tax to remove from each paycheck.

The withholding is an estimate. If you claim zero dependents and no adjustments, more money is withheld — which means a larger refund in April but less money in your pocket now. If you claim more dependents or adjust the form to reduce withholding, you keep more of each paycheck but may owe money when you file your return. The IRS publishes withholding tables that employers use to calculate the exact amount based on your pay frequency and W-4 entries.

Social Security and Medicare Taxes

Social Security tax is 6.2% of your gross wages, up to a wage cap that changes each year. In 2024, the cap is $168,600, meaning once you earn that much in a calendar year, no more Social Security tax is withheld. Medicare tax is 1.45% of all your gross wages with no cap. Both are deducted from your paycheck automatically.

Your employer matches these amounts — they pay an additional 6.2% for Social Security and 1.45% for Medicare on your behalf. These employer contributions do not come from your paycheck; the employer sends them directly to the government. If you earn over $200,000 (or $250,000 if married filing jointly), an additional 0.9% Medicare tax is withheld from your wages.

How Self-Employment Tax Works

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, and it totals 15.3% (12.4% for Social Security up to the wage cap, plus 2.9% for Medicare). You calculate this on Schedule SE and pay it when you file your tax return, or in quarterly estimated tax payments if you expect to owe $1,000 or more.

Self-employed people can deduct half of their self-employment tax as an adjustment to income, which reduces their taxable income. You still owe the full 15.3%, but the deduction lowers the federal income tax you pay on top of it. Quarterly estimated payments are due April 15, June 15, September 15, and January 15 of the following year.

Adjusting Your Withholding

If you receive a large refund every April, it means too much was withheld from your paychecks. You can adjust this by submitting a new W-4 to your employer. Increasing the number of dependents you claim or adding an adjustment for other income will reduce your withholding and put more money in your paycheck now.

If you owe money each year, you can reduce your withholding by claiming fewer dependents or making a negative adjustment on your W-4. The goal is to have roughly the right amount withheld so you do not owe or receive a large refund. You can change your W-4 at any time — there is no limit on how often you can update it. The change takes effect on your next paycheck.

What Happens to Payroll Taxes

Federal income tax withholding goes into the general Treasury and funds federal government operations. Social Security tax funds the Social Security program, which pays retirement, disability, and survivor benefits. Medicare tax funds the Medicare program, which pays for hospital insurance and medical coverage for people 65 and older and some younger people with disabilities.

Your employer sends all withheld taxes to the IRS on a regular schedule — usually monthly or semi-weekly depending on the size of the payroll. The IRS matches these deposits to your Social Security number so the payments are credited to your account. When you file your tax return, the IRS compares what was withheld to what you actually owe.

Other Payroll Deductions That Are Not Taxes

Your paycheck may also show deductions that are not payroll taxes. These include health insurance premiums, retirement plan contributions (like a 401(k)), flexible spending account contributions, and union dues. These are separate from federal income tax, Social Security, and Medicare. Some are taken before taxes are calculated (pre-tax), which lowers your taxable income. Others are taken after taxes (post-tax).

State and local income taxes, if your state or city has them, are also withheld separately from federal payroll taxes. The amount varies by state and locality. Some states have no income tax, while others withhold a percentage similar to federal tax. Your W-4 does not control state withholding — most states have their own withholding forms or use federal withholding as a starting point.

Frequently Asked Questions

Why is my paycheck less than I expected?

Federal income tax, Social Security tax (6.2%), and Medicare tax (1.45%) are all withheld automatically. You may also have health insurance, retirement contributions, or state taxes removed. The amount withheld for federal income tax depends on your W-4 form. If you claimed zero dependents, more is withheld. You can reduce withholding by submitting a new W-4 to your employer.

Can I stop payroll taxes from being withheld?

No. Social Security and Medicare taxes are mandatory and cannot be stopped. Federal income tax withholding is also required, though you can adjust how much is withheld by changing your W-4. If you believe you will owe no federal tax for the year, you can claim exempt on your W-4, but this is only valid for one year and must be renewed each January.

What if my employer withheld the wrong amount?

The IRS compares what your employer withheld to what you actually owe when you file your return. If too much was withheld, you receive a refund. If too little was withheld, you owe the difference. You can also adjust your W-4 mid-year if you realize the withholding is wrong, and the change will take effect on your next paycheck.

Do I have to pay payroll taxes if I work part-time?

Yes. Payroll taxes are withheld from all wages, regardless of whether you work full-time or part-time. The percentage rates are the same. If you work multiple part-time jobs, each employer withholds based on the W-4 you gave them, which can result in under-withholding if your combined income is high.

What is the difference between gross pay and net pay?

Gross pay is your total earnings before any deductions. Net pay is what you take home after payroll taxes, health insurance, retirement contributions, and other deductions are removed. Your pay stub shows both amounts so you can see what was withheld and why.