Your paycheck: W-4, withholding and Social Security taxes

Step 1 — Fill out Form W-4 when you start

Form W-4, the “Employee’s Withholding Certificate,” tells your employer how much federal income tax to withhold (take out) from each paycheck (IRS — About Form W-4). Your employer pays that money to the IRS in your name (IRS — Tax withholding).

The 2026 form has five steps (IRS — Form W-4):

• Step 1: your name, address, Social Security number and filing status.
• Steps 2–4, only if they apply: more than one job or a working spouse, dependents, other income or deductions, and extra withholding.
• Step 5: your signature. Without it, the form isn’t valid.

Why it matters. If too little is withheld, you’ll generally owe tax when you file and may owe a penalty; if too much is withheld, you’ll generally get a refund (IRS — Form W-4). Without a W-4, your employer withholds as if you were single, with no other entries (IRS — Topic 753).

You can change it. A new W-4 must take effect no later than the first payroll period ending on or after the 30th day after your employer receives it (IRS — Topic 753). The IRS suggests a new one each year and when your situation changes (IRS — About Form W-4).

“Exempt” is narrow. It’s only for people who had no federal income tax liability last year and expect none this year, and it lasts one calendar year (IRS — Topic 753); the 2026 form says to renew it by February 16, 2027 (IRS — Form W-4). Social Security and Medicare taxes are still withheld (IRS — Publication 15).

Step 2 — Nonresident for tax? Follow Notice 1392

Not sure if you’re a nonresident for tax purposes? See our tax residency guide. The W-4 tells nonresidents to read IRS Notice 1392 first (IRS — Form W-4). Based on the notice (revised January 2020) and the IRS’s 2026 employer guide, nonresidents (IRS — Notice 1392; IRS — Publication 15):

• check “Single or Married filing separately,” whatever their marital status;
• don’t claim dependent credits in Step 3, except in limited cases the IRS describes;
• write “Nonresident Alien” or “NRA” below Step 4(c), or use the nonresident field if the employer’s online system has one;
• don’t claim exemption from withholding;
• don’t use the IRS Tax Withholding Estimator.

You can’t enter an ITIN instead of a Social Security number; if you don’t have one, contact the Social Security Administration (SSA) (IRS — Notice 1392). See our Social Security number guide.

More withheld than from your coworkers? Nonresidents can’t claim the standard deduction, so employers add an amount to their wages only to figure withholding; it isn’t on the W-2 and doesn’t raise the tax actually owed (IRS — Publication 15). Pay exempt under a tax treaty uses Form 8233 instead of a W-4 (IRS — Notice 1392).

Step 3 — Read your pay stub

The main parts of a pay stub, as the federal Consumer Financial Protection Bureau (CFPB) explains them (CFPB — Understanding your pay stub):

• Gross pay: what you earned before anything is taken out.
• Deductions: taxes, insurance premiums and other programs, such as a 401(k) retirement plan or health insurance.
• Net pay: gross pay minus all deductions — your “take-home” pay.
• YTD (year to date): totals since the start of the year.

The tax lines usually include federal income tax, Social Security (“FICA SS”), Medicare (“FICA Medicare”) and state income tax, which not every state has (CFPB). Some counties and cities tax income too (USAGov — State and local taxes). See our state income taxes guide.

Federal law requires employers to keep accurate records of hours worked and wages paid, but not to give you a pay stub (DOL — FLSA FAQ). Either way, keep your own record of your hours.

Check the pay itself. The federal minimum wage is $7.25 an hour (DOL — Minimum Wage). Many states set a higher minimum, and employers must follow both laws (DOL — State Minimum Wage Laws; DOL — Minimum Wage). Unless your job is exempt, hours over 40 in a workweek must be paid at least one and a half times your regular rate (DOL — Overtime). More on your rights: finding a job.

Step 4 — Understand Social Security and Medicare taxes

FICA taxes (Federal Insurance Contributions Act) are Social Security and Medicare taxes (IRS — Topic 751). The current employee rates are 6.2% for Social Security and 1.45% for Medicare, and your employer pays the same again (IRS — Topic 751). Social Security tax stops at a yearly wage limit, $184,500 for 2026; Medicare has no limit (IRS — Topic 751). The Social Security benefits you and your family may get depend on the earnings on your record (SSA — Earnings record).

Who doesn’t pay them. Tax residents pay them like U.S. citizens, and nonresidents generally do too, with exceptions based on their visa (IRS — Aliens employed in the U.S.). According to the IRS, nonresident students, scholars, teachers, trainees and researchers in F-1, J-1, M-1 or Q-1 status are exempt on pay for work that USCIS allows and that carries out the purpose of their stay — for example, on-campus student jobs (up to 20 hours a week, 40 during summer vacation) and practical training (IRS). The exemption doesn’t cover spouses and children in F-2, J-2 or M-2 status, or people who become tax residents (IRS — Foreign student liability). Students: see our international student taxes guide. “Totalization agreements” with some countries may also affect what you owe (IRS — Aliens employed in the U.S.).

Withheld by mistake? Ask your employer for a refund first. If you can’t get it all back, the IRS lets you claim it with Forms 843 and 8316 (IRS — Foreign student liability).

Step 5 — Check your withholding during the year

The IRS suggests checking your withholding every January and after big changes, such as a new job, marriage or a new child (IRS — Tax Withholding Estimator). Its estimator uses your recent pay stubs, doesn’t ask for your name or Social Security number, and can produce a pre-filled W-4 for your employer (IRS — Tax Withholding Estimator). Nonresidents follow Notice 1392 instead (Step 2).

The 2026 W-4’s Deductions Worksheet now includes deductions such as for qualified tips and overtime, and some deductions require a Social Security number (IRS — Form W-4). The IRS notes that tips and overtime pay are still subject to income and payroll taxes (IRS — Tax law changes).

Step 6 — Check your W-2 and your earnings record

Form W-2 shows your wages and the taxes withheld for the year (IRS — W-2 help). For 2026, employers generally must give it to you by February 1, 2027; if you leave and ask for it, within 30 days of your request or your last paycheck, whichever is later (IRS — W-2 instructions). Your employer also files it with SSA, and your Social Security and Medicare benefits are figured from W-2 information (IRS — Topic 752). So your name and number must be right:

• Name. Employers use the name and number on your Social Security card. After a name change, such as at marriage, the IRS says to request an updated card from SSA; until you show it, your employer keeps the old name (IRS — Publication 15). The W-4 adds: if your name doesn’t match your card, contact SSA at 800-772-1213 so you get credit for your earnings (IRS — Form W-4).
• Number arrived late? If it came after your employer filed your W-2, the employer files a corrected one, Form W-2c (IRS — Publication 15). So share it as soon as you have it.
• Other errors. Ask your employer to fix them. If they aren’t fixed by the end of February, call the IRS at 800-829-1040 or book a Taxpayer Assistance Center appointment (IRS — W-2 help). W-2 missing? See our first tax return guide.
• Your earnings record. From age 18, you can review it in a personal my Social Security account; SSA suggests checking in August that last year’s amount is correct (SSA — Earnings record). If earnings are missing, for example because of a wrong name or number, gather proof such as W-2s or pay stubs and contact SSA (SSA).