Mortgage Interest Deduction in Illinois
State income tax rate
4.95%
Itemized deductions allowed
❌ No
State-Level Mortgage Interest Deduction
Illinois has a flat 4.95% income tax but does not allow itemized deductions — only a standard exemption system. Mortgage interest is not deductible at the Illinois state level.
Frequently Asked Questions
Keep reading
CalculatorMortgage Interest Deduction CalculatorRun your own numbers with Illinois rates applied.GuideMortgage Interest Deduction by StateHow the federal rules interact with each state's conformity and limits.GuideIs a Home Equity Loan Tax Deductible?The 2018 rules, and the use test that decides whether your interest qualifies.GuideMortgage Points: What They Cost and When They Pay OffPoints are prepaid interest, and on a purchase they can be deducted in the year paid.
Rate reflects the top marginal state income tax rate for 2026 per the Tax Foundation. Whether a deduction helps depends on your full return, including whether itemizing beats the federal standard deduction. General information, not tax advice.