Skip to contentNerdwallet icon

Illinois State Income Tax: Rates and Who Pays in 2026

Illinois income taxes are calculated differently than in some other states, levying a flat personal income tax rather than following a tiered structure.

Andy Rosen
Sabrina Parys
Updated
The Illinois income tax rate is a flat 4.95%. Unlike the federal government and many other states, Illinois does not have tax brackets that impose higher rates on people who earn more.
Illinois state income taxes are due April 15, the same day as federal income taxes. The state grants an automatic six-month extension to anyone who can't file on time, pushing the deadline to Oct. 15. Note, however, that even taxpayers who get an extension must still pay any taxes owed by the April 15 filing deadline.

Illinois state income tax rates and tax brackets

Illinois does not have tax brackets, so calculating your rate should be pretty simple. If you have a dollar or $1 billion that's subject to Illinois income tax, you owe 4.95% of that money to the state.
However, Illinois has a handful of tax-saving programs that may affect your final tax bill, and these can apply differently based on income or other life circumstances.
» MORE: See what federal tax bracket you’re in

Illinois state income tax deductions and credits

Here are some key tax-reduction programs in Illinois and how to qualify.

Illinois earned income tax credit (EITC)

In Illinois, the EITC is strongly tied to the federal program of the same name. If you qualify for the federal program, you'll generally qualify for the state credit. Because it's a refundable tax credit, the credit can reduce your taxes owed on a dollar-for-dollar basis, and it can even result in a refund.
In 2026, the Illinois earned income tax credit ranges from $130 to $1,609, and is calculated as 20% of the federal amount.

Illinois K-12 education expense credit

The Illinois K-12 education expense credit can knock up to $750 off your tax bill if you spent more than $250 on qualified education expenses. These expenses include tuition, book rentals and lab fees.
There are some exceptions, however. You can't claim day care, preschool or college costs, for example. Certain materials or equipment — such as musical instruments — that are used for qualified programs may not be acceptable if they "are not significantly used up during the school year."
The credit is not for everyone. Taxpayers whose federal adjusted gross income exceeds $250,000 ($500,000 for married couples filing jointly) are not eligible to claim this tax benefit.

Illinois tax deductions

Illinois also differs from the federal government in the way it handles tax deductions. The state doesn't have itemized deductions or a standard deduction in the traditional sense. Rather, Illinois offers a set of specific expenses that can be subtracted from your taxable income. These include:
  • Some contributions to college savings accounts.
  • Contributions to ABLE accounts, which are savings plans for people with disabilities.
  • Income from tax-exempt bonds issued by the state or local Illinois governments.

Illinois exemption allowance

In addition, Illinois has what is called an exemption allowance, which is a set amount that most people who earn a paycheck can knock off their taxable income. The exemption for tax year 2025 is a maximum of $5,700 for married couples filing jointly ($2,850 for single filers).
The difference between the exemption allowance and the standard deduction is that you can still take it even if you have other subtractions from your income, as mentioned above. With the standard deduction, generally speaking, you have to choose whether to take it or add up your itemized deductions and claim those instead.
Note that there are some taxpayers who won’t qualify for the full exemption (or potentially any at all), including:
  • If someone else can claim you as a dependent and you have your own income.
  • If your adjusted gross income was more than $250,000 ($500,000 for married couples filing jointly).

Do I have to pay Illinois state income tax?

You have to file an Illinois state tax return if:
  • You’re an Illinois resident and you’re required to file a federal tax return.
  • You’re an Illinois resident without a federal filing requirement, but your Illinois income exceeds your exemption allowance.
  • You’re not an Illinois resident but earned a certain amount of money from a source in Illinois during the tax year.
  • You lived in Illinois for part of the year and had income during that time.
Illinois also has reciprocity with the neighboring states of Iowa, Kentucky, Michigan and Wisconsin, which means those states don't tax Illinois residents who work within their borders. So if you live in Illinois and work in Iowa, Kentucky, Michigan or Wisconsin, you'll pay tax to your home state.
Likewise, residents of Iowa, Kentucky, Michigan and Wisconsin who work in Illinois are not required to file an Illinois state income tax return unless they earned certain Illinois nonwage income, such as lottery winnings.
» Learn more: See state income tax brackets here

Am I a resident for Illinois state income tax purposes?

There are three types of residency statuses when it comes to Illinois state tax. They determine what portion of your income the state will tax.
If your Illinois residency type is ...
… Illinois taxes this part of your income
Resident
All income from all sources inside and outside Illinois.
Part-year resident
All income received while a resident, plus income from Illinois sources while a nonresident.
Nonresident
Income from Illinois sources if your adjusted gross income is higher than your Illinois exemption allowance.

4 things to know about Illinois state tax

  1. If you're an Illinois resident with a simple income tax situation who makes below a certain amount, you may be able to file a free federal return via IRS Free File. You may also qualify for a free state return through MyTax Illinois.
  2. Another option for your state taxes is commercial tax software, though this often comes with an extra fee.
  3. If you can’t afford your tax bill, Illinois offers payment plans that you can set up online.
  4. If you’re curious about where your Illinois state tax refund is, check the status of your state refund.
Explore more on
Taxes
Article sources
NerdWallet writers are subject matter authorities who use primary, trustworthy sources to inform their work, including peer-reviewed studies, government websites, academic research and interviews with industry experts. All content is fact-checked for accuracy, timeliness and relevance. You can learn more about NerdWallet's high standards for journalism by reading our editorial guidelines.
Back to top
Related articles
IRS Free File: What It Is, How It Works
Sabrina Parys's profile picture
2
By Sabrina Parys, Tina Orem
10 Key IRS Tax Forms, Schedules and Publications for 2026
Tina Orem's profile picture
By Tina Orem
1040 Form: What It Is, How to Fill One Out in 2026
Tina Orem's profile picture
2
By Tina Orem, Sabrina Parys