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 gross amount (what you earned) is larger than the net amount (what you take home). The difference is payroll taxes. Your employer is required by law to deduct these taxes and send them to the federal government on your behalf. You do not have a choice about whether to pay them — they come out automatically.

There are four main payroll taxes. Social Security tax and Medicare tax together are called FICA taxes. Federal income tax withholding is separate. If you live in a state with a state income tax, your employer also withholds that. Some cities tax income too. This article focuses on the federal taxes that apply everywhere.

Key Takeaways

  • Social Security tax is 6.2 percent of your wages, and Medicare tax is 1.45 percent; your employer pays an equal amount on top, but you only see your half on your paycheck.
  • Federal income tax withholding depends on how much you earn and what you put on your W-4 form — it is not a fixed percentage like Social Security and Medicare.
  • Your employer sends all withheld taxes to the IRS, not to you, so the money never reaches your bank account.
  • The taxes you pay now go toward current Social Security and Medicare payments to retirees and disabled people, not into a personal account with your name on it.

How much Social Security and Medicare tax you pay

Social Security tax is 6.2 percent of your wages. Medicare tax is 1.45 percent of your wages. These are fixed rates that do not change based on your income or personal situation. Together they are called FICA — Federal Insurance Contributions Act.

There is a cap on Social Security tax. In 2024, you pay Social Security tax only on the first $168,600 of your annual wages. Once you earn more than that in a year, your employer stops taking Social Security tax from your paycheck for the rest of that year. Medicare tax has no cap — you pay 1.45 percent on all your wages, no matter how much you earn. If you earn over $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.

Your employer also pays Social Security and Medicare tax on your behalf — the same amounts you pay. So the total Social Security and Medicare cost is actually double what you see withheld, but only your half appears on your paycheck.

How federal income tax withholding works

Federal income tax withholding is different from Social Security and Medicare because the rate is not fixed. How much your employer withholds depends on two things: how much you earn and what you tell your employer on your W-4 form.

The W-4 is a form you fill out when you start a job. It asks about your filing status (single, married, head of household), how many dependents you have, and whether you have other income or jobs. Based on your answers, the IRS provides a withholding calculation. Your employer uses that to figure out how much federal income tax to take from each paycheck.

If you want less tax withheld (so you take home more each paycheck), you can claim more allowances or dependents on your W-4. If you want more tax withheld (so you owe less or get a bigger refund at tax time), you can claim fewer. You can change your W-4 whenever your situation changes — when you get married, have a child, get a second job, or your spouse starts working.

Where the money goes after it leaves your paycheck

Your employer collects the Social Security tax, Medicare tax, and federal income tax withholding from your paycheck and sends it to the IRS. The employer also sends their own matching Social Security and Medicare taxes. This happens on a schedule — usually monthly or quarterly, depending on the size of the business.

The Social Security tax you pay goes into the Social Security trust fund, which pays current benefits to retirees, disabled workers, and survivors of deceased workers. The Medicare tax you pay goes into the Medicare trust fund, which pays for hospital insurance (Part A) for people 65 and older and some younger people with disabilities. The federal income tax withholding goes into the general Treasury and funds federal government operations.

You do not have a personal account where your payroll taxes sit waiting for you. The money you pay in Social Security tax today goes to pay someone else's benefits today. When you retire, your benefits will come from the Social Security taxes that workers are paying then.

Why your paycheck is smaller than your salary

If your job posting or offer letter says you will earn $50,000 a year, your actual take-home will be less. The difference is not just payroll taxes — it also includes any health insurance premiums, retirement plan contributions, or other deductions your employer takes out.

But payroll taxes are usually the largest deduction. For someone earning $50,000 a year, Social Security and Medicare together take about 7.65 percent, or roughly $3,825 per year. Federal income tax withholding varies widely depending on your W-4, but it might be another $4,000 to $6,000 per year for a single person with no dependents. State and local taxes, if they apply where you live, come out on top of that.

This is why your first paycheck often surprises people. The gross pay looks reasonable, but the net pay — the amount actually deposited into your account — is noticeably smaller.

Self-employment taxes if you work for yourself

If you are self-employed or run your own business, you do not have an employer to withhold payroll taxes. Instead, you pay self-employment tax yourself, usually quarterly. Self-employment tax covers both your share and your employer's share of Social Security and Medicare — so the rate is double: 12.4 percent for Social Security and 2.9 percent for Medicare, totaling 15.3 percent.

You calculate self-employment tax based on your net business income (what you earn minus business expenses). You can deduct half of your self-employment tax when you file your tax return, which reduces your taxable income slightly. You also owe federal income tax on your business income, but that is separate from self-employment tax.

Self-employed people often set aside money each month to cover these taxes, since they do not have an employer doing the withholding automatically. Many use a tax professional or accounting software to calculate what they owe.

What happens at tax time with payroll taxes

In January, your employer sends you a W-2 form showing how much you earned and how much was withheld for federal income tax, Social Security, and Medicare. You use this form to file your tax return.

When you file, the IRS compares what was withheld from your paychecks to what you actually owe based on your full tax situation. If too much was withheld, you get a refund. If too little was withheld, you owe money. Social Security and Medicare taxes are not refundable — you pay them and they go into the trust funds. But federal income tax withholding can result in a refund or a bill.

This is why many people get a tax refund even though they did not overpay — their employer simply withheld more federal income tax than necessary based on their actual tax liability. Adjusting your W-4 can help you get closer to breaking even at tax time instead of getting a large refund or owing a large amount.

Frequently Asked Questions

Can I opt out of paying payroll taxes?

No. Payroll taxes are mandatory for all employees. Your employer is required by law to withhold them. The only exception is certain religious groups that have received IRS approval to be exempt from Social Security and Medicare taxes, but this is rare and requires specific documentation.

What is the difference between gross pay and net pay?

Gross pay is your total earnings before any deductions. Net pay is what you actually receive after payroll taxes, health insurance premiums, retirement contributions, and other deductions are taken out. Your paycheck shows both amounts so you can see the difference.

Do I get Social Security and Medicare taxes back at tax time?

No. Social Security and Medicare taxes (FICA) are not refundable. Once you pay them, they go into the trust funds and you cannot get them back. Only federal income tax withholding can result in a refund if too much was taken out.

Why does my paycheck change from month to month if my salary is the same?

Federal income tax withholding can vary if you have irregular income, bonuses, or overtime. Some months you earn more, which changes the withholding calculation. Also, if you changed your W-4 during the year, the new withholding takes effect on your next paycheck after the change is processed.

What if my employer did not withhold payroll taxes?

Contact your employer immediately and ask them to correct it. Employers are legally required to withhold and remit these taxes. If they do not, you may still owe the taxes when you file your return, and your employer could face penalties and legal action. If your employer is not withholding, report it to the IRS or your state labor department.