Personal Finance

Understanding Your Paycheck: Every Deduction Explained

Why your take-home pay is so much lower than your salary, broken down line by line.

7 min read · Updated January 2026

Gross Pay vs. Net Pay

Gross pay is your total earnings before anything is withheld. Net pay (take-home pay) is what actually hits your bank account after all deductions. For most US employees, net pay is 70-80% of gross pay, depending on income level, state, and benefit elections.

Federal Income Tax

Withheld based on the information on your W-4 form (filing status, dependents, additional withholding) and the IRS's progressive tax brackets. You don't pay one flat rate on your whole income — each portion of income is taxed at the rate for its bracket, so your effective rate is lower than your top marginal rate.

FICA: Social Security and Medicare

Together these are called FICA (Federal Insurance Contributions Act) taxes, and your employer matches both amounts on your behalf (a cost to them, not visible on your pay stub).

State and Local Income Tax

Varies enormously — nine states have no state income tax at all (as of this writing), while others have progressive brackets similar to the federal system. Some cities (like New York City) add their own local income tax on top of state tax.

Pre-Tax Deductions

These reduce your taxable income before federal (and often state) tax is calculated — a genuine tax advantage:

Post-Tax Deductions

Taken out after taxes are calculated, so they don't reduce your taxable income:

Reading Your Actual Pay Stub

A typical pay stub shows, in order: gross pay for the period, each deduction line with its own amount, and net pay. Year-to-date (YTD) columns show cumulative totals for the calendar year — useful for tracking whether you're on pace to hit contribution limits (like the 401(k) annual max) or the Social Security wage base.

Use a Paycheck Calculator to estimate your own take-home pay and compare it against your actual stub — a mismatch is worth investigating with your payroll department.

Frequently Asked Questions

Why does my Social Security withholding stop partway through the year?

Social Security tax only applies up to an annual wage base limit ($168,600 for 2024) — once your year-to-date wages cross that threshold, Social Security withholding stops for the rest of the calendar year, though Medicare tax continues on all wages.

What's the difference between a Traditional and Roth 401(k) on my paycheck?

Traditional 401(k) contributions are pre-tax, reducing your taxable income now (you pay tax later on withdrawal); Roth 401(k) contributions are post-tax, so they don't reduce current taxable income but qualified withdrawals in retirement are tax-free.

Why is my employer's FICA match not shown on my pay stub?

Your pay stub only shows what's withheld from your pay, not what your employer separately contributes on your behalf — the employer's matching FICA contribution is a cost to them that doesn't appear as a deduction from your wages.

This article is provided for general informational purposes only and does not constitute financial, tax, legal, medical, or professional advice. Always verify important decisions with a qualified professional or official source.