What Gets Taken Out of Your Paycheck and Why

Your employer withholds payroll taxes from each paycheck for three separate programs: federal income tax, Social Security, and Medicare. Federal income tax goes to the U.S. Treasury. Social Security and Medicare are FICA taxes (Federal Insurance Contributions Act), and they fund those two programs specifically. Your employer also pays a matching amount for Social Security and Medicare on your behalf — that part does not come from your check.

The amount withheld depends on what you earn, how often you are paid, what you claimed on your W-4 form, and your state and local tax situation. The calculation happens the same way at every employer, using IRS withholding tables or software that applies the same rules.

Some states and cities also withhold income tax. Whether yours does depends on where you live and work, not on your employer's choice. If you live in one state and work in another, you may owe tax to both, or your employer may withhold for the state where you work.

Key Takeaways

  • Federal income tax withholding is based on your W-4 form, which tells your employer how much to hold back based on your expected annual income and personal situation.
  • Social Security tax is 6.2 percent of your gross pay (up to a yearly earnings cap that changes each year), and Medicare tax is 1.45 percent with no cap.
  • Your employer matches the Social Security and Medicare amounts you pay, but that matching portion does not reduce your paycheck.
  • State and local income tax withholding varies by location and is separate from federal withholding.
  • Your pay stub shows gross pay, each tax withheld, and net pay (what you actually receive).

How Federal Income Tax Withholding Works

Federal income tax withholding starts with the W-4 form you fill out when you are hired. On it, you claim dependents, note other income, and indicate whether you have a spouse who also works. Your employer uses this information plus IRS withholding tables to calculate how much federal tax to hold from each paycheck.

The withholding tables assume you will earn the same amount in every pay period for the whole year. If you are paid weekly, the table calculates what you would earn annually at that weekly rate, then divides the annual tax by 52. If you are paid biweekly, it divides by 26. This is why your withholding changes if you get a raise or take unpaid leave — the calculation restarts based on your new rate.

You can change your W-4 at any time during the year by submitting a new form to your employer's payroll department. If you find you are getting a large refund every April, you can claim more allowances to reduce withholding. If you owe money at tax time, you can claim fewer allowances to increase withholding. The IRS provides a W-4 calculator on its website (irs.gov) to help you figure out the right number.

Social Security and Medicare Tax Rates

Social Security tax is 6.2 percent of your gross pay, but only on earnings up to a cap. That cap changes each year — in 2024 it was $168,600, meaning once you earn that much in a calendar year, no more Social Security tax is withheld from that year's paychecks. Your employer still withholds the matching 6.2 percent, but you stop paying into the program once you hit the cap.

Medicare tax is 1.45 percent of all your gross pay with no earnings cap. You pay it on every dollar you earn, no matter how much. If your income exceeds $200,000 (or $250,000 if married filing jointly), an additional 0.9 percent Medicare tax applies to the amount over that threshold. This additional tax is withheld by your employer if your pay crosses that line.

Both Social Security and Medicare are FICA taxes. Your employer withholds them and sends them to the IRS along with the matching amounts your employer pays. Unlike federal income tax, which is based on your W-4 choices, FICA withholding is automatic and the same for everyone at the same pay level.

Reading Your Pay Stub

Your pay stub shows the calculation in this order: gross pay (what you earned before any deductions), then each tax withheld, then net pay (what you actually receive). The stub lists federal income tax, Social Security, Medicare, and any state or local tax separately so you can see exactly where your money goes.

The stub also shows year-to-date totals for each tax. This is useful because it tells you whether you have hit the Social Security earnings cap (your Social Security withholding will stop once you do, but your year-to-date total will show you are close). It also shows you how much you have paid in total for the year, which you will need when you file your tax return.

If you notice a tax withheld that you do not recognize, or if the amounts seem wrong, contact your payroll department. Common issues include a W-4 that was not processed correctly, a name or Social Security number mismatch, or a state tax withholding that should not be there. Payroll can usually fix these within one pay period.

What Happens If You Have Multiple Jobs

When you work more than one job, each employer withholds federal income tax based on the W-4 you give them, without knowing about your other income. This can result in too little tax being withheld overall, because each employer calculates as if that job is your only income.

To fix this, you can claim fewer allowances on your W-4 at one or both jobs, or you can ask your employer to withhold an extra flat amount from each paycheck. You fill out a new W-4 and write the extra amount in the space for "other income." For example, if you work two part-time jobs, you might ask one employer to withhold an extra $50 per paycheck to cover the gap.

Social Security and Medicare withholding is not affected by multiple jobs — each employer withholds the correct percentage regardless. However, if your combined earnings exceed the Social Security cap, you may overpay Social Security tax across both jobs. When you file your tax return, you can claim a credit for the overpayment.

State and Local Income Tax Withholding

Forty-one states and the District of Columbia have state income tax. Your employer withholds it if you live in one of those states, based on a state W-4 form (some states call it a different name). The calculation works the same way as federal withholding — your state W-4 tells your employer how much to hold.

Nine states have no 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 live in one of these states, your employer does not withhold state income tax.

If you work in a state different from where you live, your employer usually withholds for the state where you work. Some states have reciprocal agreements that let you claim an exemption from withholding if you live in a neighboring state. A few cities also withhold local income tax — New York City and Philadelphia are the most common. Your pay stub will show each tax separately.

Adjusting Your Withholding During the Year

You do not have to wait until next year to change your withholding. If you get a big bonus, inherit money, get married, have a child, or experience any major change in income or life situation, you can submit a new W-4 to your employer at any time. The new withholding takes effect on the next paycheck after your employer processes the form.

The IRS W-4 calculator (available at irs.gov) walks you through your situation and tells you what to claim. You will need to know your expected income for the year, whether you are married, how many children you have, and whether you have other income. The calculator accounts for the standard deduction and tax brackets so you withhold the right amount.

If you are self-employed or have income that is not subject to withholding, you may need to make quarterly estimated tax payments instead. That is a separate process from payroll withholding and is covered in the self-employment tax section of the IRS website.

Frequently Asked Questions

Why do I owe taxes at the end of the year if my employer already withheld taxes?

Withholding is an estimate based on your W-4 and pay frequency. If your actual tax liability is higher than what was withheld — because you had a raise partway through the year, worked overtime, or had other income — you will owe the difference. You can adjust your W-4 mid-year to increase withholding if you see this pattern happening.

What is the difference between gross pay and net pay?

Gross pay is what you earned before any deductions. Net pay is what you actually receive after federal income tax, Social Security, Medicare, and any state or local taxes are withheld. Your pay stub shows both so you can see the full picture.

Can my employer withhold more than the IRS tables say?

Yes. You can ask your employer to withhold an extra flat amount from each paycheck by writing it on your W-4 in the space for additional withholding. This is common when people have multiple jobs or other income sources and want to avoid owing money at tax time.

What happens to the taxes my employer withholds?

Your employer sends federal income tax, Social Security, and Medicare to the IRS, usually monthly or biweekly depending on the size of the payroll. State and local taxes go to your state and city. When you file your tax return, the IRS matches what was withheld to your return and either refunds the difference or bills you for what you still owe.

Do I get the employer matching portion of Social Security and Medicare?

The employer match does not go to you directly — it goes into the Social Security and Medicare trust funds on your behalf. It counts toward your future benefits, but you do not see it on your paycheck. It is a cost to your employer, not a deduction from your pay.