Between Social Security, Medicare, and federal income tax, the federal government takes out of your paycheck at least 7.65% for FICA plus a federal income tax bite that runs from 10% to 37% of your taxable income, depending on how much you earn and what you put on your W-4.1Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 The FICA piece is a flat rate that hits nearly every dollar. The income tax piece is an estimate your employer calculates from the W-4 you filled out, and it can move up or down based on your filing status, credits, and pre-tax benefit elections.
The Flat FICA Bite: 7.65% Off the Top
Two payroll taxes come out of almost every paycheck at fixed rates set by the Federal Insurance Contributions Act. Social Security tax is 6.2% of your gross wages. Medicare tax is 1.45%. Together, that’s 7.65% withheld regardless of your filing status or dependents.2Office of the Law Revision Counsel. 26 U.S. Code 3101 – Rate of Tax
Social Security has a ceiling. In 2026, you pay the 6.2% only on the first $184,500 you earn during the year.3Social Security Administration. 2026 Cost-of-Living Adjustment (COLA) Fact Sheet Once your year-to-date wages cross that line, Social Security withholding stops for the rest of the year. Medicare has no ceiling. Every dollar you earn is subject to the 1.45%.
Higher earners pay a little more. If your wages cross $200,000 in a year, or $250,000 for a married couple filing jointly, an Additional Medicare Tax of 0.9% applies to earnings above the threshold.4Internal Revenue Service. Topic No. 560, Additional Medicare Tax Your employer starts withholding this extra 0.9% as soon as your wages pass $200,000, regardless of filing status. If your joint threshold is actually $250,000, the difference is reconciled on your return.
Your employer pays a matching 6.2% and 1.45% out of its own pocket. Those amounts do not show up on your pay stub and do not reduce your check.5Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates Employers do not match the 0.9% surtax.
Federal Income Tax Withholding
Federal income tax is the bigger and more variable piece. It uses a progressive bracket system: your first dollars are taxed at the lowest rate, and only the dollars above each threshold get taxed at the next rate up. Your employer withholds an estimated amount from every check based on the W-4 you submitted.6Office of the Law Revision Counsel. 26 U.S. Code 3402 – Income Tax Collected at Source What comes out of your paycheck is not the final tax bill. It’s an advance payment toward what you’ll owe when you file.
Before any bracket math applies, your income is reduced by the standard deduction. For 2026, that deduction is $16,100 for single filers, $32,200 for married couples filing jointly, and $24,150 for heads of household.1Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Only the income above your standard deduction is taxable, and the brackets apply to that reduced number.
The 2026 federal income tax brackets for a single filer are:7Internal Revenue Service. Revenue Procedure 2025-32
- 10% on taxable income up to $12,400
- 12% on $12,401 to $50,400
- 22% on $50,401 to $105,700
- 24% on $105,701 to $201,775
- 32% on $201,776 to $256,225
- 35% on $256,226 to $640,600
- 37% on income over $640,600
For married couples filing jointly, the thresholds are roughly double the single amounts. The 10% bracket runs up to $24,800, and the 12% bracket covers $24,801 to $100,800.7Internal Revenue Service. Revenue Procedure 2025-32 Because the brackets stack, someone earning $60,000 does not pay 22% on the whole amount. Only the slice that lands inside each bracket is taxed at that bracket’s rate, so the effective rate you actually pay is always lower than your top bracket.
What Your W-4 Controls
Your employer decides how much federal income tax to hold back based on the Form W-4 you filed. It asks for three things: your filing status, any credits you want to claim (like the Child Tax Credit), and adjustments for things like a second job or non-wage income.8Internal Revenue Service. About Form W-4, Employee’s Withholding Certificate
Filing status moves the needle most. Choosing married filing jointly gives you a larger standard deduction and wider brackets, which pulls less tax from each check than choosing single. If you have qualifying children under 17, claiming the Child Tax Credit on the W-4 (worth up to $2,200 per child for 2026) directly cuts your withholding.9Internal Revenue Service. Child Tax Credit
Two-job households need extra care. If you work two jobs at once, or your spouse also works, each job’s default withholding can miss the fact that your combined income pushes you into a higher bracket. The W-4 includes a Multiple Jobs Worksheet, and the IRS Tax Withholding Estimator at irs.gov can tell you how much extra to withhold.10Internal Revenue Service. Tax Withholding Estimator Any additional amount goes on Step 4(c) of the W-4 for your highest-paying job.11Internal Revenue Service. Tax Withholding Estimator FAQs
Life events shift the math too. Marriage, divorce, a new child, or buying a home can all change what you owe. Updating your W-4 soon after any of these keeps your paycheck withholding close to your real liability.
Pre-Tax Deductions That Lower the Withholding
Some deductions come out of your gross pay before your employer calculates income tax. These pre-tax deductions shrink the wage figure that withholding is based on, so less federal income tax leaves your paycheck.
Traditional 401(k) contributions do the heaviest lifting. In 2026, you can defer up to $24,500 of salary into a traditional 401(k). If you’re 50 or older, you can add another $8,000 in catch-up contributions, and workers aged 60 through 63 get a higher catch-up limit of $11,250.12Internal Revenue Service. Retirement Topics – 401(k) and Profit-Sharing Plan Contribution Limits Every dollar into a traditional 401(k) lowers the income used to calculate your federal withholding. Roth 401(k) contributions are made after tax and don’t reduce your current withholding.
If you’re on a high-deductible health plan, a Health Savings Account contribution through payroll goes even further. For 2026, the HSA limit is $4,400 for self-only coverage and $8,750 for family coverage.13Internal Revenue Service. Revenue Procedure 2025-19 Payroll HSA contributions are typically excluded from both income tax and FICA, which no other common deduction achieves.
Employer-sponsored health, dental, and vision premiums usually come out pre-tax as well. A $200 biweekly health premium reduces the gross pay used to compute income tax withholding by that $200. These benefit deductions generally do not reduce your Social Security and Medicare wages unless they flow through a qualifying cafeteria plan under the tax code.
A Sample Paycheck
Consider a single filer earning $52,000 a year, no dependents, paid biweekly. Gross pay per check is $2,000.
- Social Security at 6.2%: $124.00
- Medicare at 1.45%: $29.00
- Federal income tax withholding: about $156 (varies with W-4 settings)
The income tax estimate comes from applying the 2026 brackets to $35,900 in taxable income ($52,000 minus the $16,100 standard deduction). The first $12,400 is taxed at 10%, and the remaining $23,500 at 12%, for a full-year tax of roughly $4,060, or about $156 per biweekly check.7Internal Revenue Service. Revenue Procedure 2025-32
After the three federal deductions, take-home pay is about $1,691 per check, or roughly 84.5% of gross. Contributing $200 per check to a traditional 401(k) would cut the federal income tax withholding further because the taxable wage figure drops, partially offsetting the retirement contribution.
State income tax is a separate deduction that varies by where you live and work, and it’s not part of what the federal government takes.
What Happens at Year-End
Paycheck withholding is an estimate. When you file, you compare the totals withheld all year (Boxes 2, 4, and 6 on your W-2) against the actual tax you owe.14Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026) Too much withheld means a refund. Too little means you owe the difference, and possibly an underpayment penalty.
You generally avoid the penalty if your withholding and estimated payments together cover at least the smaller of 90% of the current year’s tax or 100% of last year’s tax.15Office of the Law Revision Counsel. 26 U.S. Code 6654 – Failure by Individual to Pay Estimated Income Tax If your prior-year adjusted gross income was over $150,000 ($75,000 if married filing separately), the safe harbor rises to 110% of the prior year’s tax.16Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
You can also trip a penalty if your withholding was fine for the year overall but concentrated too late, while the tax was owed earlier. Most W-2 employees are safe because their withholding is spread evenly. The problem can surface if you change jobs mid-year or take a large bonus in one quarter. Checking your pay stubs against your W-2 at year-end is a good habit either way.