State income tax is a tax on wages, investment income, and other earnings that your state government collects

Not every state has an income tax. Nine states — Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming, and New Hampshire — do not tax wage income at all. New Hampshire taxes only investment income, not wages. The remaining 41 states and the District of Columbia collect income tax on wages, and most also tax investment income, retirement distributions, and other earnings.

The amount you owe depends on three things: your income level, your state's tax rate, and which deductions and credits your state allows. Most states use a progressive tax system, meaning the rate increases as your income rises. Some states use a flat rate that applies to all income levels. Your employer usually withholds state income tax from each paycheck, but the amount withheld may not match what you actually owe, which is why you file a state tax return.

State income tax is separate from federal income tax. You file both a federal return to the IRS and a state return to your state's tax agency. If you live in a state with no income tax but work in a state that has one, you may owe tax to the state where you work, not where you live — the rules vary by state.

Key Takeaways

  • Nine states have no income tax on wages, while 41 states and Washington D.C. collect income tax on earnings.
  • Most states use a progressive tax rate that increases with income, though some use a single flat rate for all earners.
  • Your employer withholds state income tax from your paycheck, but you file a state tax return to reconcile what was withheld against what you actually owe.
  • State income tax rules differ from federal tax rules, and you may owe tax to a state where you work even if you do not live there.
  • Tax credits and deductions vary widely by state and can significantly reduce the amount of tax you owe.

How state income tax rates work

Most states that collect income tax use a progressive tax bracket system. Your income is divided into ranges, and each range is taxed at a different rate. For example, a state might tax the first $10,000 of income at 3 percent, the next $20,000 at 5 percent, and income above that at 7 percent. You do not pay the highest rate on all your income — only on the portion that falls into that bracket.

A smaller number of states use a flat tax, where everyone pays the same percentage regardless of income level. Colorado, Illinois, Indiana, Kentucky, Massachusetts, Michigan, Mississippi, Missouri, North Carolina, Pennsylvania, and Utah use flat tax systems. The rate ranges from about 3 percent to 5.75 percent depending on the state.

Tax rates also vary significantly between states. Some states have top rates below 4 percent, while others exceed 10 percent. California, Hawaii, and Oregon have the highest top marginal rates. If you move to a different state or change jobs across state lines, your tax burden can change substantially even if your income stays the same.

What income is taxed and what is not

Most states tax wages and salaries — the money you earn from a job. They also tax self-employment income if you run a business or freelance. Investment income such as capital gains, dividends, and interest is taxed in most states, though some states exempt certain types of investment income or tax them at lower rates.

Retirement income is handled differently across states. Some states exempt Social Security benefits entirely. Others tax retirement account withdrawals (like 401(k) and IRA distributions) but exempt or partially exempt pension income. A few states exempt all retirement income. If you are retired or receiving distributions from retirement accounts, your state's rules on retirement income can make a significant difference in your tax bill.

Certain types of income are not taxed by any state. These include life insurance payouts, gifts, inheritances, and workers' compensation benefits. Some states also exempt military pay for active-duty service members or income from certain bonds.

Deductions and credits that reduce your state tax

States offer deductions that reduce the amount of income subject to tax. The most common is the standard deduction, which works similarly to the federal standard deduction — you subtract a set amount from your income before calculating tax. Some states also allow itemized deductions for mortgage interest, property taxes, charitable donations, and medical expenses, though the rules differ from federal rules.

Tax credits are different from deductions because they reduce the tax you owe dollar-for-dollar rather than reducing your taxable income. Many states offer credits for dependent children, education expenses, earned income (similar to the federal Earned Income Tax Credit), and property taxes paid. Some states offer credits for retirement savings or contributions to college savings plans.

The value of deductions and credits varies widely by state and by your income level. A deduction worth $1,000 saves you more money in a high-tax state than in a low-tax state. Some credits phase out as your income rises, meaning higher earners receive less benefit. Checking your state's tax website or speaking with a tax preparer can help you understand which deductions and credits explore to your situation.

How withholding works and why it may not match what you owe

When you start a job, you complete a state withholding form (similar to the federal W-4). This form tells your employer how much state income tax to deduct from each paycheck. Your employer sends that withheld money to the state on your behalf throughout the year. The amount withheld is an estimate based on the information you provide.

The withholding may be too high or too low depending on your actual tax situation. If you have multiple jobs, significant investment income, or claim dependents, the standard withholding calculation may not be accurate. If too much is withheld, you receive a refund when you file your state tax return. If too little is withheld, you owe money when you file.

You can adjust your withholding during the year by submitting a new withholding form to your employer. If you expect to owe money at tax time, increasing your withholding now reduces the amount you will owe later. If you expect a large refund, decreasing your withholding lets you keep more money in each paycheck instead of lending it to the state interest-free.

Filing your state tax return

You file your state tax return by the same important date as your federal return, which is typically April 15. You will need your W-2 forms from your employer (or 1099 forms if you are self-employed), records of any state income tax withheld, and documentation of deductions or credits you plan to claim. Most states accept returns filed electronically through tax software or through a tax preparer.

If you lived in more than one state during the year, you may need to file returns in multiple states. Generally, you file a resident return in the state where you lived on December 31 and non-resident returns in any other states where you earned income. Some states have reciprocal agreements that prevent you from being taxed by both states on the same income, but you still need to file to claim the exemption.

If you did not have enough income to owe federal tax, you may still need to file a state return because state income thresholds are sometimes lower than federal thresholds. Check your state's tax website to see whether you are required to file based on your income level and filing status.

States with no income tax and special tax situations

If you live in Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, or Wyoming, you pay no state income tax on wages. This can be a significant advantage if you earn a high income. However, these states often make up the lost revenue through higher sales taxes, property taxes, or other fees, so the overall tax burden is not necessarily lower.

If you work in one state but live in another, the state where you work generally has the right to tax your wages. However, some states have agreements to avoid double taxation. For example, if you live in Pennsylvania and work in New Jersey, you may be able to claim a credit on your Pennsylvania return for taxes paid to New Jersey. The rules are specific to each pair of states, so check both states' tax websites if this applies to you.

Military service members on active duty may be exempt from state income tax in the state where they are stationed, even if they are stationed far from their home state. Some states also offer tax breaks for military retirement pay or veterans' income. If you are military or a veteran, your state's tax website will have information on these exemptions.

Frequently Asked Questions

Do I have to file a state tax return if I did not earn much income?

It depends on your state's income threshold and your filing status. Most states require you to file if your income exceeds a certain amount, which is usually lower than the federal threshold. Check your state's tax agency website and enter your income and filing status to see whether you are required to file. Even if you are not required to file, you may want to file anyway if you had taxes withheld, because you could receive a refund.

What happens if I do not file a state tax return?

If you owe state income tax and do not file, the state can assess penalties and interest on the unpaid amount. If you are owed a refund, the state will hold it until you file. The statute of limitations for the state to assess unpaid tax is typically three to seven years, depending on the state. If you have not filed in previous years, you can file back returns, though you may owe penalties.

Can I claim the same deductions on my state return that I claim on my federal return?

Not always. State deductions and credits are separate from federal ones, and the rules differ. Some states follow federal rules closely, while others have their own rules. For example, some states do not allow itemized deductions at all, or they cap the amount of property tax you can deduct. Review your state's tax instructions or website to see which deductions and credits you can claim on your state return.

If I move to a state with no income tax, do I still owe tax to my old state?

You owe tax to your old state only for the portion of the year you lived there. If you moved on June 30, you file a part-year resident return in your old state for January through June and a resident return in your new state for July through December. You will need to provide documentation of your move, such as a lease or utility bill showing your new address and the date you moved.

Why is my state tax refund taking so long?

State tax refunds typically take two to eight weeks to process, depending on the state and whether you filed electronically or by mail. If you filed by mail, add time for processing. If you claimed certain credits or deductions that require verification, the state may take longer to review your return. You can check the status of your refund on your state's tax agency website.