Your employer removes taxes before you see your pay

The amount taken from your paycheck depends on four things: your gross pay (what you earn before deductions), your W-4 form (which you fill out when hired), your state and local tax rates, and whether you have other income or dependents. Federal income tax, Social Security tax, and Medicare tax are removed from almost every paycheck. Your state may also take state income tax, and some cities take local income tax.

The exact dollar amount varies by person because it is based on your filing status, number of dependents, and how much you earn. Two people earning the same salary can have different deductions if they filled out different W-4 forms or live in different states.

Key Takeaways

  • Federal income tax, Social Security tax (6.2%), and Medicare tax (1.45%) are removed from nearly all paychecks, plus any state or local income tax your location charges.
  • Your W-4 form controls how much federal tax your employer withholds; changing it changes your deduction without changing your actual tax bill at year-end.
  • Social Security and Medicare taxes have a maximum: Social Security stops after you earn about $168,600 in a year, but Medicare continues on all income.
  • You can see exactly what was deducted by looking at your pay stub, which lists each tax line separately.
  • If too much or too little is withheld, you will owe money or receive a refund when you file your tax return, not because the withholding was wrong, but because your actual tax liability differs from what was withheld.

Federal income tax: what your W-4 controls

When you start a job, you fill out a W-4 form (officially the "Employee's Withholding Certificate"). This form tells your employer how much federal income tax to remove from each paycheck. The more you claim on the W-4, the less tax is withheld. The fewer you claim, the more is withheld.

The W-4 asks for your filing status (single, married, head of household), the number of dependents you claim, and whether you have other jobs or income. Your employer uses this information to calculate a withholding amount based on IRS tables. If you change jobs, get married, have a child, or your income changes significantly, you can fill out a new W-4 to adjust the withholding.

Changing your W-4 does not change how much tax you actually owe at the end of the year—it only changes how much is taken out now. If you withhold too little, you will owe money when you file your return. If you withhold too much, you will receive a refund.

Social Security and Medicare taxes: fixed percentages

Social Security tax is 6.2% of your gross pay (up to a limit). Medicare tax is 1.45% of your gross pay with no limit. These are separate from federal income tax and are removed automatically—you do not control them with a W-4.

Social Security tax stops once you earn about $168,600 in a calendar year (this amount changes annually). If you work two jobs and earn more than that combined, the second employer may withhold Social Security tax on income above the limit, but you can claim a credit when you file your return. Medicare tax continues on all income, no matter how much you earn.

Your employer also pays an equal amount of Social Security and Medicare tax on your behalf (6.2% and 1.45%), but that money does not come from your paycheck—it is a separate employer cost.

State and local income taxes

Most states charge income tax, but the rate and rules vary widely. Some states have no income tax at all (including Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, and Wyoming). Others charge between 1% and 13% depending on your income level.

If your state has income tax, your employer will withhold it based on a state W-4 form you fill out (some states use the federal W-4, others have their own). A few cities—including New York City, Philadelphia, and Washington, D.C.—also charge local income tax, which is withheld the same way.

State and local tax withholding works the same as federal: the amount taken out is an estimate, and you settle up when you file your state and local returns.

Reading your pay stub to see what was deducted

Your pay stub (or earnings statement) shows every deduction line by line. It lists your gross pay at the top, then breaks down federal income tax, Social Security, Medicare, state tax, local tax, and any other deductions (like health insurance or retirement contributions). At the bottom is your net pay—the amount you actually receive.

If a deduction seems wrong, check your W-4 first. If you recently changed jobs or your life situation changed, you may have filled out a W-4 that does not match your current situation. You can request a new W-4 from your HR or payroll department at any time.

If you notice a deduction you do not recognize, ask your payroll department what it is. Some employers deduct union dues, garnishments, or other court-ordered payments that you may not have authorized directly.

Why your withholding might not match your actual tax bill

The amount withheld from your paycheck is an estimate. Your actual tax bill depends on your total income for the year, deductions you claim, credits you receive, and life events like marriage or having a child. If your estimate was off, you will either owe money or receive a refund when you file your return.

Common reasons for a mismatch: you worked only part of the year, you had a large bonus, you have investment income, you claimed too many or too few dependents on your W-4, or your spouse also works and you both claimed the same dependents. If you consistently owe money or get a large refund, you can adjust your W-4 to change the withholding.

A refund means you gave the government an interest-free loan during the year. Some people prefer this because it forces them to save. Others adjust their W-4 to take home more pay each month and handle the tax bill themselves.

How to adjust your withholding

If you want to change how much is withheld, fill out a new W-4 and give it to your payroll or HR department. You do not need your employer's permission—you can change it whenever your situation changes. The new withholding takes effect on your next paycheck (or within a pay period or two, depending on your employer's schedule).

Use the IRS W-4 calculator on the IRS website (irs.gov) to figure out what to claim. It asks questions about your income, dependents, and other jobs, then tells you what to enter on the form. This is free and takes about 10 minutes.

If you are self-employed or have income that is not subject to withholding, you may need to make estimated tax payments quarterly instead of relying on paycheck withholding. Talk to a tax professional or check the IRS website for guidance on your specific situation.

Frequently Asked Questions

Can I claim zero on my W-4 to get a bigger refund?

Yes, but it means less money in each paycheck. Claiming zero withholds the maximum federal income tax. You will likely receive a refund when you file, but you are essentially lending money to the government interest-free for the year. Most people adjust their W-4 to match their actual tax situation rather than use it as a forced savings tool.

Why is my paycheck less than I expected?

Deductions include federal income tax, Social Security (6.2%), Medicare (1.45%), state income tax (if your state charges it), and local income tax (if your city charges it). Some employers also deduct health insurance premiums, retirement contributions, or other benefits. Check your pay stub to see the breakdown.

What happens if my employer withholds the wrong amount?

You will settle it when you file your tax return. If too much was withheld, you receive a refund. If too little was withheld, you owe money. To prevent this going forward, fill out a new W-4 and give it to payroll. Use the IRS W-4 calculator to figure out what to claim based on your actual situation.

Do I have to pay Social Security and Medicare tax?

Yes, if you are an employee. These are mandatory payroll taxes. Self-employed people pay both the employee and employer portions (15.3% total). There is no way to opt out, but you can see the amounts on your pay stub and claim them as deductions when you file your return.

What if I work in one state but live in another?

You typically pay income tax to the state where you work, not where you live. However, some states have reciprocal agreements that change this. Check your state's tax authority website or ask your payroll department which state tax you should be paying. You may need to file returns in both states and claim a credit to avoid paying twice.