Payroll tax is money withheld from your paycheck to pay for Social Security, Medicare, and federal income tax

When you see your paycheck, the gross amount (what you earned) is higher than what you actually receive. The difference is payroll tax — money your employer sends to the federal government on your behalf. Payroll tax funds three things: Social Security retirement and disability benefits, Medicare health insurance for people 65 and older, and federal income tax that goes into the general Treasury.

Your employer withholds these taxes automatically. You do not have to do anything to pay them — they come out before you see the money. The amount withheld depends on your income, how often you are paid, and the tax form (W-4) you filled out when you started the job.

Key Takeaways

  • Payroll tax has three parts: Social Security (6.2% of your wages), Medicare (1.45%), and federal income tax (varies based on your W-4 form).
  • Your employer withholds these taxes from each paycheck and sends them to the IRS and Social Security Administration.
  • Self-employed people pay both the employee and employer portions, totaling 15.3% for Social Security and Medicare combined.
  • You can adjust how much federal income tax is withheld by updating your W-4 form with your employer.
  • Payroll taxes are separate from state income tax and local taxes, which vary by where you live and work.

The three parts of payroll tax and what each one funds

Social Security tax is 6.2% of your wages, up to a yearly cap. In 2024, you stop paying Social Security tax once you earn $168,600 in a calendar year. This money funds retirement benefits, survivor benefits for your family if you die, and disability benefits. When you reach 62 or older, you can claim Social Security retirement benefits based on how much you paid in.

Medicare tax is 1.45% of all your wages with no yearly cap — you pay it on every dollar you earn. This funds Medicare Part A (hospital insurance) and Part B (medical insurance) for people 65 and older. If you earn more than $200,000 as a single filer (or $250,000 if married filing jointly), you pay an additional 0.9% Medicare tax on the amount over that threshold.

Federal income tax withholding is the third piece. The amount depends on your W-4 form, which you complete when hired. The W-4 asks about your filing status, number of dependents, and other income. Based on your answers, your employer withholds a percentage of each paycheck. This is not a fixed rate like Social Security and Medicare — it is calculated to try to match what you will actually owe when you file your tax return in April.

How much your employer withholds and why it varies

Social Security and Medicare withholding are straightforward: 6.2% plus 1.45% equals 7.65% that comes out of every paycheck, with no variation unless you earn over the Social Security cap or the Medicare threshold. Federal income tax withholding varies person to person because it depends on your W-4 answers.

If you claim zero dependents and have no other income, your employer withholds more federal tax from each check. If you claim dependents or have a spouse who works, you withhold less. The goal is to have roughly the right amount withheld so that when you file your tax return, you either owe very little or get a refund close to zero. If too much is withheld, you get a refund. If too little is withheld, you owe money in April.

You can change your W-4 at any time by asking your employer for a new form. This is useful if your life changes — you get married, have a child, take a second job, or your spouse loses income. Updating your W-4 adjusts your withholding going forward, not retroactively.

Self-employed people and payroll tax

If you are self-employed, you pay both the employee and employer portions of Social Security and Medicare tax. This is called self-employment tax. The combined rate is 15.3% (12.4% for Social Security, 2.9% for Medicare), compared to the 7.65% an employee pays. You calculate self-employment tax on your net business income (revenue minus business expenses) using Schedule SE when you file your tax return.

Self-employed people do not have federal income tax withheld automatically. Instead, you may need to make quarterly estimated tax payments to the IRS if you expect to owe $1,000 or more when you file. These payments are due April 15, June 15, September 15, and January 15 of the following year. You can deduct half of your self-employment tax as a business expense on your tax return, which reduces your taxable income.

The difference between payroll tax and income tax

Payroll tax and income tax are not the same thing, though federal income tax withholding is part of payroll tax. Payroll tax specifically refers to Social Security, Medicare, and federal income tax withheld from your paycheck. Income tax is a broader category that includes federal, state, and local taxes on your earnings.

When you file your tax return in April, you report all your income and calculate what you actually owe in federal income tax. The withholding from your paychecks is credited against that amount. If you withheld too much, you get a refund. If you withheld too little, you pay the difference. Social Security and Medicare taxes are not refundable — once you pay them, that money goes to those programs and does not come back.

State and local taxes are separate from payroll tax

Payroll tax is federal only. Many states also withhold state income tax from your paycheck, and some cities withhold local income tax. These are separate from federal payroll tax and vary by location. Nine states have no state income tax at all: Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming, and New Hampshire (which taxes only dividends and interest, not wages).

If you work in a state or city different from where you live, you may owe tax to both places. Some states have reciprocal agreements that let you pay tax only to your home state. Your employer should withhold based on where you work, but you may need to file returns in multiple states if you moved during the year or worked in more than one state.

Frequently Asked Questions

Can I avoid paying payroll tax?

No. Payroll tax is mandatory for all employees and self-employed people. You cannot opt out of Social Security or Medicare, and federal income tax withholding is required by law. You can adjust how much federal income tax is withheld by changing your W-4, but you cannot eliminate it entirely unless you have no income.

What happens if my employer does not withhold payroll tax?

Your employer is legally required to withhold and send payroll taxes to the IRS and Social Security Administration. If they do not, you are still responsible for paying those taxes when you file your return or when the IRS contacts you. Report non-withholding to the IRS using Form 13909 (Whistleblower Form).

Do I get Social Security and Medicare taxes back when I file my return?

No. Social Security and Medicare taxes are not refundable. The money you pay in is credited to your Social Security account and Medicare trust fund. Federal income tax withholding can result in a refund if too much was withheld, but Social Security and Medicare taxes are final.

Why is my paycheck smaller than I expected?

Payroll tax is the most common reason. If you earned $2,000 gross, payroll tax alone removes roughly $153 (7.65% for Social Security and Medicare). Federal income tax withholding removes additional money depending on your W-4. Other deductions like health insurance premiums, retirement contributions, or garnishments also reduce your take-home pay.

Do I need to file a tax return if payroll tax was withheld?

Usually yes, even if you had taxes withheld. You file to report all your income, claim deductions, and reconcile what you paid in withholding against what you actually owe. If too much was withheld, you get a refund. Some people with very low income may not be required to file, but filing often results in a refund of withheld taxes.