Payroll taxes are split between you and your employer, and the total rate depends on which tax you're looking at

Payroll taxes come out of your paycheck in three main forms: Social Security, Medicare, and federal income tax withholding. Social Security and Medicare are fixed percentages that don't change based on how much you earn. Federal income tax withholding varies based on what you claim on your W-4 form. Your employer pays a matching amount for Social Security and Medicare — money that doesn't show up on your paycheck but counts as a real cost to them.

The rates are set by federal law and stay the same across all states, though some states add their own income tax on top. Self-employed people pay both the employee and employer portions themselves, which is why their total rate is roughly double what a W-2 employee sees withheld.

Key Takeaways

  • Social Security tax is 6.2% of your wages up to a yearly cap (the cap changes each year), and your employer matches that amount.
  • Medicare tax is 1.45% of all your wages with no cap, and your employer matches that amount; high earners pay an extra 0.9% on income over a threshold.
  • Federal income tax withholding is not a fixed rate — it depends on your W-4 form, how many dependents you claim, and your filing status.
  • Your employer's matching taxes are a real cost to them but do not appear on your paycheck; self-employed people pay both portions themselves.
  • State and local income taxes vary by location and are separate from federal payroll taxes.

Social Security tax: 6.2% with an annual earnings cap

Social Security tax is 6.2% of your gross wages, taken from your paycheck. Your employer pays another 6.2% on your behalf. The catch is that this tax only applies to earnings up to a certain amount each year — in 2024, that cap was $168,600. Once you hit that cap, no more Social Security tax comes out of your paycheck for the rest of the year, even if you earn more.

The cap changes every year based on wage growth in the economy. This means high earners stop paying Social Security tax partway through the year, while lower-wage workers pay it on every dollar they make. Self-employed people pay both the employee and employer portions — 12.4% total — but they can deduct half of it on their tax return.

Medicare tax: 1.45% with no cap, plus 0.9% extra for high earners

Medicare tax is 1.45% of your gross wages, and your employer matches it. Unlike Social Security, there is no annual cap — you pay Medicare tax on every dollar you earn, no matter how much you make. This means someone earning $500,000 a year pays Medicare tax on all of it.

If you earn above a certain threshold, you pay an additional 0.9% Medicare tax on the income over that amount. For 2024, the threshold was $200,000 for single filers and $250,000 for married couples filing jointly. This extra tax only comes out of your paycheck — your employer does not match it. Self-employed people pay the full 2.9% Medicare tax (1.45% employee + 1.45% employer portions) plus the 0.9% surtax if they're above the income threshold.

Federal income tax withholding: varies based on your W-4

Federal income tax withholding is not a fixed percentage like Social Security and Medicare. Instead, your employer withholds an amount based on what you tell them on your W-4 form. The W-4 asks for your filing status, number of dependents, and any additional income or adjustments. The IRS provides a withholding calculator on their website to help you figure out what to claim.

If you claim too many dependents or adjustments, too little tax gets withheld and you may owe money when you file your return. If you claim too few, more tax comes out and you'll get a refund. Some people intentionally adjust their W-4 to get a bigger refund, though that means giving the government an interest-free loan throughout the year. You can change your W-4 at any time — you don't have to wait until next year.

State and local income taxes vary by where you live and work

Most states have their own income tax, which is withheld separately from federal taxes. The rates and rules vary widely. Some states have no income tax at all (like Texas, Florida, and Wyoming), while others tax income at rates ranging from around 1% to over 13%. A few states tax only certain types of income, like dividends or capital gains.

If you work in one state but live in another, you may have to file returns in both places. Some states have reciprocal agreements that prevent double taxation, but not all do. Local taxes in cities or counties add another layer in some places. Your paycheck stub should show exactly what's being withheld for state and local taxes, so you can see the total being taken out.

What your employer pays on top of what you see withheld

Your paycheck shows only what's taken from your wages. Your employer also pays payroll taxes that you never see: 6.2% for Social Security and 1.45% for Medicare, matching what comes out of your check. These are real costs to the employer, factored into what they budget for labor.

For a worker earning $50,000 a year, the employer's matching taxes total about $3,825 (6.2% + 1.45% = 7.65% of $50,000). This is why employers care about payroll taxes — they affect the total cost of hiring. Self-employed people have to pay both portions themselves, which is why their self-employment tax is roughly double what a W-2 employee sees withheld.

How to read your paycheck stub and understand the deductions

Your paycheck stub breaks down every tax and deduction. Look for these lines: "Social Security" or "OASDI" (6.2% up to the annual cap), "Medicare" (1.45%), "Federal Income Tax" or "FIT" (varies), and any state or local income tax. Some stubs also show "Medicare Surtax" if you're a high earner. Add up all the taxes and you'll see the total percentage of your gross pay going to taxes.

If the numbers don't match what you expect, check your W-4 first — that's the most common reason federal withholding is off. If you think Social Security or Medicare is being calculated wrong, contact your employer's payroll department. Errors are rare but do happen, especially if you have multiple jobs or changed jobs during the year.

Frequently Asked Questions

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

Social Security is an insurance program, not a savings account. You pay in while working, and the money goes to current retirees and disabled workers. Whether you get back more than you paid in depends on how long you live and when you claim benefits — it's not a direct transaction. The program is designed so that most people do receive benefits, but the amount varies.

Does my employer's matching taxes count as income to me?

No. Your employer's matching Social Security and Medicare taxes are a cost to them, not income added to your paycheck. They don't show up on your W-2 as wages. However, they do count toward your Social Security earnings record, which determines how much you can receive in benefits later.

What happens if I have two jobs — do I pay double payroll taxes?

You pay Social Security and Medicare tax on both paychecks, but you can claim a credit on your tax return if you overpaid Social Security tax. This happens because each employer withholds up to the annual cap without knowing about your other job. Medicare has no cap, so you pay it on all earnings from both jobs with no credit. File your tax return to recover the overpayment.

Can I opt out of Social Security or Medicare taxes?

No. These are mandatory for all W-2 employees and self-employed people. Some religious groups have limited exemptions from self-employment tax, but they must apply through the IRS and meet strict requirements. Regular employees cannot opt out.

Why is my federal withholding so high or so low?

Your W-4 form controls federal withholding. If too much is coming out, you claimed too few dependents or adjustments. If too little is coming out, you claimed too many. Use the IRS withholding calculator on irs.gov to recalculate, then submit a new W-4 to your employer. You can change it anytime during the year.