Most workers pay income tax to two governments: the federal government and, in most cases, their state. The two systems have separate rules, rates, and forms, and your state can significantly change your overall tax burden. Understanding the split helps you plan, especially if you move or work across state lines.

Two separate systems

The federal income tax is uniform across the country, with the same seven brackets and rules for everyone regardless of where they live. State income taxes are set independently by each state, with their own brackets, deductions, and credits. You typically file a federal return and a separate state return each year. The two are calculated on overlapping but not identical definitions of income.

How states vary

States take three broad approaches: some use progressive brackets like the federal system, some charge a single flat rate, and several charge no income tax on wages at all. As of 2025, a handful of states — including Florida, Texas, and Washington — do not tax wage income, though some tax other income like capital gains. Rates in states that do tax income range from under 3% to over 13% at the top. Where you live can swing your total income tax by thousands of dollars.

Different starting points and breaks

Many states begin their calculation from your federal adjusted gross income or taxable income, then apply their own adjustments. Some conform closely to federal rules, while others decouple on items like retirement income, Social Security benefits, or specific deductions. States also offer their own credits, such as for renters, child care, or college savings contributions. These differences mean your state taxable income is rarely identical to your federal figure.

Living and working across state lines

If you live in one state and work in another, you may owe tax to both, though a credit for taxes paid to another state usually prevents true double taxation. Remote workers can face tricky rules about which state has the right to tax their income. Moving mid-year generally means filing part-year returns in each state. Anyone with multi-state income should track where they earned it to file correctly.

A worker earning $80,000 pays the same federal tax whether they live in Texas or California, but Texas charges no state income tax while California could add several thousand dollars. The federal layer is identical; the state layer makes the difference.

Key takeaways

  • Federal income tax is uniform nationwide; state income tax rules are set by each state.
  • States may use progressive brackets, a flat rate, or no wage income tax at all.
  • Many states start from your federal AGI, then apply their own adjustments and credits.
  • Living in one state and working in another can create multi-state filing, usually with a credit to avoid double tax.
  • Your choice of state can change your total income tax bill substantially.

Common mistakes

FAQ

Do all states have an income tax?

No, several states levy no tax on wage income and instead rely on sales, property, or other taxes to fund their budgets.

If I work remotely, which state taxes me?

It depends on the states involved, but generally your resident state taxes all your income while the state where you physically work may also tax the income earned there, with a credit to offset the overlap.