Illinois Income Tax for Married Filing Separately (2026)
Filing as a Married Filing Separately in Illinois? Heres everything you need to know about the state income tax: brackets, standard deduction, and worked examples for common income levels.
Illinois Tax Brackets (2026)
For Married Filing Separately in Illinois, the tax brackets for 2026 are:
| Taxable Income | Tax Rate |
|---|
The standard deduction for Married Filing Separately in Illinois is $14,600. You can take this deduction or itemize, whichever results in a lower tax bill.
$75,000 Income Example
Lets say youre a Married Filing Separately in Illinois earning $75,000/year. After the $14,600 standard deduction, your taxable income is $60,400. Your Illinois state tax is approximately:
Your effective state tax rate is 4.0%. This is on top of federal income tax (and local taxes if applicable).
More Examples for Married Filing Separately in Illinois
| Gross Income | Taxable Income | State Tax | Effective Rate |
|---|---|---|---|
| $50,000 | $35,400 | $1,752 | 3.5% |
| $75,000 | $60,400 | $2,989 | 4.0% |
| $100,000 | $85,400 | $4,227 | 4.2% |
| $150,000 | $135,400 | $6,702 | 4.5% |
| $200,000 | $185,400 | $9,177 | 4.6% |
Illinois-Specific Deductions and Credits
Beyond the standard deduction, Illinois offers several tax deductions and credits that can reduce your tax bill:
- Retirement income exclusion: Some states exclude retirement income for seniors
- Property tax credit: Available in some states for homeowners and renters
- Earned Income Tax Credit (EITC): Some states have their own EITC in addition to the federal one
- Child and dependent care credit: Available in many states
- Education credits: 529 plan contributions or tuition deductions may be available
Use the Illinois income tax calculator to model your specific situation, including deductions and credits.
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Filing Illinois state taxes depends on your residency status:
- Illinois residents: File Form ST-IL-1 with your state Department of Revenue. Due April 15 (same as federal).
- Part-year residents: File Form ST-IL-1-PR, reporting only income earned while a resident
- Non-residents: File Form ST-IL-1-NR if you earned income in Illinois
Frequently Asked Questions
What is the Illinois tax bracket for Married Filing Separately?
The Illinois tax brackets for Married Filing Separately range from 4.95% to 4.95%. The standard deduction is $14,600.
How much Illinois tax do I owe on a $75K income as a Married Filing Separately?
On a $75,000 income as a Married Filing Separately in Illinois, you owe approximately $2,989 in state income tax. Your effective state tax rate is 4.0%.
What is the standard deduction for Married Filing Separately in Illinois?
The standard deduction for Married Filing Separately in Illinois is $14,600. You can take this or itemize, whichever is higher.