Tax withheld from your paycheck based on your W-4 elections and IRS tax brackets.
Common paystub code: FWT / FIT / FED
Federal Income Tax (FIT) is the tax your employer withholds from each paycheck based on the information you provided on Form W-4. The amount withheld depends on your filing status, number of dependents, additional withholding, and the current IRS tax brackets (10% to 37% for 2026). Unlike FICA, the amount withheld is an estimate — your actual tax liability is reconciled when you file your annual tax return. If too much was withheld, you get a refund; too little means you owe.
On your paystub, FIT is typically labeled "FWT," "FIT," or "FED." It's often the largest single deduction from your gross pay, and unlike FICA it's not a flat rate — it's computed using the IRS percentage method tables published in Publication 15-T each year.
The 2026 federal tax brackets (single filer): 10% on income up to $11,925; 12% from $11,926 to $48,475; 22% from $48,476 to $103,350; 24% from $103,351 to $197,300; 32% from $197,301 to $250,525; 35% from $250,526 to $626,350; and 37% above $626,351. Brackets are roughly doubled for married filing jointly.
How withholding is computed. Your employer takes your gross pay, annualizes it (e.g., $2,000 bi-weekly × 26 = $52,000/year), subtracts the standard deduction (or your W-4 dependent credits), then applies the bracket math to that annualized number. The yearly tax is then divided by your number of pay periods to give the per-paycheck withholding. This is why getting a raise mid-year can cause "bracket creep" if your employer hasn't updated your projection.
W-4 changes everything. The 2020 redesigned W-4 eliminated allowances. Now you adjust withholding by claiming dependents (Step 3) or adding extra dollars per paycheck (Step 4c). If your refund last year was huge, you're over-withholding — submit a new W-4 to claim more dependents or reduce extra withholding so you keep more cash each paycheck.
Common mistake: Assuming your highest bracket applies to ALL your income. The U.S. uses a marginal system — only income WITHIN a bracket is taxed at that bracket's rate. Earning $50,000 doesn't mean you pay 22% on all $50,000; you pay 10% on the first $11,925, 12% on the next chunk, and only 22% on the small portion above $48,475.
Source: IRS Publication 15-T (Federal Income Tax Withholding Methods) and Revenue Procedure 2025-32 for 2026 brackets.