How Much Is Illinois State Income Tax in 2026?

Quick Answer: A Flat 4.95% With a Small Exemption

For the 2026 tax year, Illinois taxes your income at a flat 4.95% — the same rate since 2017. Before the tax is calculated, you can subtract a personal exemption of $2,925 per person ($5,850 for married filing jointly, plus $2,925 for each dependent). There are no tax brackets, no standard deduction, and no local income taxes.

For a single filer earning $100,000, the estimated take-home pay is roughly $74,375 after federal tax, FICA, and the 4.95% Illinois tax. That is about $1,700 less than in neighboring Indiana but about $1,150 more than in California.

How Illinois Taxes Your Income in 2026

Illinois is one of only a handful of states with a constitutionally mandated flat income tax. Key facts:

• The rate is 4.95% for everyone. Whether you earn $25,000 or $250,000, the state rate is the same. In 2020, Illinois voters rejected a proposed constitutional amendment that would have allowed graduated rates.
• Personal exemption reduces taxable income. For 2026, the exemption is $2,925 per person. A single filer with a $100,000 salary pays state tax on $97,075.
• No standard deduction. Unlike the federal system, Illinois does not offer a standard deduction or itemized deductions for most filers.

No Local Income Tax, But High Sales and Property Taxes

One clear advantage: Illinois municipalities cannot levy an income tax. You will not find a Chicago city income tax or Cook County wage tax. The trade-offs show up in other taxes:

• Sales tax: The state rate is 6.25%, but local rates push Chicago's combined sales tax to approximately 10.25% — among the highest of any major U.S. city.
• Property tax: Illinois consistently ranks among the top two states for effective property tax burden, behind only New Jersey in most analyses. Homeowners in the Chicago suburbs and downstate should budget accordingly.

So while the income-tax picture is easy to calculate, your overall cost of living may still be higher than in states with a slightly higher income-tax rate but lower sales and property taxes.

Illinois Salary After Taxes: Take-Home Pay by Income Level

Here is what a single filer in Illinois can expect to keep in 2026. These estimates use the federal standard deduction of $16,100, FICA, and Illinois's 4.95% flat tax applied after the $2,925 personal exemption.

Figures use the 2026 IRS federal tax brackets, the single filer standard deduction of $16,100, FICA rates of 6.2% for Social Security (up to the $184,500 wage base) and 1.45% for Medicare, and Illinois's flat 4.95% applied to gross income minus the $2,925 personal exemption. Wages above $200,000 for single filers are also subject to an additional 0.9% Medicare tax.

Illinois vs. Other States: Where Does It Stand?

Here is the same $100,000 single-filer salary across several states in 2026:

Illinois sits in the middle of the pack for take-home pay at this income level. It beats California and New York slightly but loses to Pennsylvania and Texas. Remember: this table only measures income tax. Once you add Chicago's 10.25% sales tax and Illinois's second-highest-in-the-nation property taxes, a worker in the Chicago metro area may pay more overall than the headline income-tax rate suggests.

Retirement Income Is Fully Exempt

Illinois is one of the most retirement-friendly states in the country. All of the following are completely exempt from state income tax:

• Social Security benefits
• Public and private pension distributions
• 401(k), 403(b), and IRA withdrawals

This makes Illinois a popular destination for retirees who want access to Chicago's amenities and healthcare without paying state tax on their retirement income. The trade-off, again, is property taxes — retirees who own homes in Illinois still face some of the highest property tax bills in the nation.

How to Pay Less Tax in Illinois

Because Illinois uses a flat tax with limited deductions, your main levers are federal-side pre-tax contributions and retirement planning:

• Max out a traditional 401(k): Contributions reduce your federal taxable income and lower the income number used for some Illinois credits. In 2026, the employee limit is $24,500 ($32,500 if you are 50 or older). Illinois does not tax qualified retirement distributions, so you avoid state tax on that money entirely.
• Contribute to an HSA: Payroll contributions avoid federal income tax and FICA. For 2026, the limits are $4,400 for self-only coverage and $8,750 for family coverage.
• Use a health FSA: Set aside up to $3,400 in 2026 pre-tax for medical expenses, reducing your federal taxable income.
• Claim the Illinois Earned Income Credit (EIC): Illinois matches a portion of the federal EITC. Low- and moderate-income workers should file a tax return to claim it, even if they are not otherwise required to file.
• Plan where you live within Illinois: Because there is no local income tax, your state tax does not change by city. But property taxes and sales taxes vary widely — research county and municipal rates if you are flexible.

2026 Federal Tax Basics for Illinois Workers

Your Illinois tax is only part of the story. Here are the key 2026 federal numbers:

• Standard deduction (single): $16,100
• Standard deduction (married filing jointly): $32,200
• Standard deduction (head of household): $24,150

2026 Federal Tax Brackets for Single Filers

Frequently Asked Questions

What is the Illinois state income tax rate in 2026?

A flat 4.95% on taxable income. The Illinois constitution requires a flat rate, and voters rejected a 2020 amendment that would have allowed graduated brackets.

How much is $100,000 after taxes in Illinois?

A single filer earning $100,000 pays approximately $13,170 in federal income tax, $7,650 in FICA, and $4,805 in Illinois state tax, leaving an estimated take-home pay of about $74,375.

Does Illinois have local income taxes?

No. Illinois municipalities and counties cannot levy an income tax. The 4.95% state tax is the only income tax below the federal level.

Does Illinois tax Social Security or retirement income?

No. Illinois exempts all retirement income, including Social Security, pensions, and 401(k) or IRA distributions. It is one of the most retirement-friendly states for income tax.

What is the Illinois personal exemption for 2026?

$2,925 per person — $5,850 for a married couple filing jointly, plus $2,925 for each dependent. This exemption is subtracted from your income before the 4.95% tax is applied.

How can I calculate my exact Illinois after-tax income?

Use our free Illinois after tax income calculator to get a personalized estimate based on your exact income, filing status, 401(k), and HSA contributions.