Yes, property taxes are deductible in Illinois, and homeowners actually get two separate benefits for the same payment. On your federal return, property taxes count toward the itemized State and Local Tax (SALT) deduction, capped at $40,000 starting in 2025. On your Illinois return, you can claim a non-refundable credit equal to 5% of the property taxes you paid on your principal residence. The two work independently, use different forms, and have different eligibility rules.
The Federal SALT Deduction
When you itemize on Schedule A, property taxes paid to Illinois counties reduce your federal taxable income. They are combined with state income taxes under a single cap. For 2025, that cap jumped from $10,000 to $40,000 for single filers and married couples filing jointly, with annual inflation adjustments through 2029.1Internal Revenue Service. Topic no. 503, Deductible Taxes Married filing separately caps at $20,000 total, split evenly at $10,000 each.
The higher cap matters in Illinois, where property tax bills routinely blew past the old $10,000 limit on their own. A homeowner paying $12,000 in property taxes and $5,000 in state income taxes can now deduct the full $17,000 instead of being stopped at $10,000.
Phaseout for High Earners
The $40,000 cap phases down for taxpayers with modified adjusted gross income above roughly $500,000 (about $250,000 for married filing separately). The reduction equals 30% of every dollar above that threshold, and the cap cannot drop below $10,000 ($5,000 for separate filers).1Internal Revenue Service. Topic no. 503, Deductible Taxes A married couple with $600,000 in modified AGI would see the cap reduced by $30,000, leaving an effective SALT limit of $10,000. Below $500,000, the full cap applies.
The AMT Caveat
If you owe the Alternative Minimum Tax, state and local tax deductions are completely disallowed under that calculation. For 2026, the AMT exemption is $140,200 for married couples filing jointly and $90,100 for single filers, with phaseouts beginning at $1,000,000 and $500,000 respectively.2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Households roughly between $750,000 and $1.5 million in income are the most likely to land in AMT, where the SALT deduction loses its value entirely.
The Illinois 5% Property Tax Credit
Illinois gives homeowners a state income tax credit equal to 5% of the property taxes paid on a principal residence during the tax year.3Illinois Department of Revenue. Publication 108, Illinois Property Tax Credit A credit works differently from a deduction. Instead of lowering the income that gets taxed, it reduces your state tax bill dollar-for-dollar. Pay $10,000 in property taxes, get $500 subtracted from what you owe Illinois.
The credit is non-refundable. It can bring your state tax liability down to zero but no further, and you cannot carry any unused portion to a future year.4Illinois Department of Revenue. Pub-108, Illinois Property Tax Credit
One wrinkle catches people off guard. Before calculating the 5%, you must subtract any portion of your property tax that qualifies as a business expense deduction on your federal return, whether or not you actually claimed it.3Illinois Department of Revenue. Publication 108, Illinois Property Tax Credit If 15% of your property tax is attributable to a business use of the home, the credit applies only to the remaining 85%.
What Property Qualifies
The federal deduction and the Illinois credit do not cover the same properties, and treating them as interchangeable is a common filing mistake.
The federal SALT deduction applies to property taxes paid on any real property you own, provided the tax is levied uniformly for general public welfare.1Internal Revenue Service. Topic no. 503, Deductible Taxes Second homes, vacation properties, and undeveloped land all qualify. Rental property taxes get deducted as a business expense on Schedule E instead of on Schedule A, so they don’t go through the SALT cap at all.
The Illinois credit is narrower. It covers only property taxes paid on your principal residence, and you must own the home.5Cornell Law School Legal Information Institute. Ill. Admin. Code tit. 86, 100.2180 – Credit for Residential Real Property Taxes (IITA 208) Vacation homes, rentals, and investment land are out. If part of the property is used for business or rental, you can only claim the credit on the residential share.
Mobile home owners should note one boundary: the mobile home privilege tax (also called the local services tax) does not qualify for the Illinois credit, even if the mobile home is your principal residence.3Illinois Department of Revenue. Publication 108, Illinois Property Tax Credit
When the Payment Counts
Both benefits are tied to when you actually paid the tax, not when it was assessed. Taxes that left your hands (or your lender’s hands) between January 1 and December 31 count for that tax year. If you fell behind and paid two years in the same calendar year, you claim both in that year. Penalties and interest never count.4Illinois Department of Revenue. Pub-108, Illinois Property Tax Credit
If your lender holds an escrow account, the date that matters is when the lender disburses the funds to the county, not when you made your monthly mortgage payment.6Internal Revenue Service. Tax Information for Homeowners Your year-end mortgage statement or Form 1098 will show the total property taxes paid from escrow during the year.
If You Bought or Sold a Home
At closing, property tax responsibility is split by date. For the federal deduction, the seller is treated as paying the taxes through the day before the sale and the buyer from the sale date forward. Each party deducts their share on that year’s return if they itemize, regardless of who actually wrote the check at the closing table.6Internal Revenue Service. Tax Information for Homeowners
The Illinois credit follows a different timeline. If you sold your home during the tax year, you can include the prior year’s tax plus any prorated current-year tax you paid at closing. If the home sat vacant before the sale, the vacant period doesn’t count.3Illinois Department of Revenue. Publication 108, Illinois Property Tax Credit
Buyers face a quirk in the opposite direction. You cannot use the property taxes shown on the closing statement in the year you purchase the home, because those taxes belong to the seller for credit purposes. The following year, you can claim the taxes attributable to the months you owned and occupied the property.3Illinois Department of Revenue. Publication 108, Illinois Property Tax Credit Buy a home in October 2025, and three months of 2025 property taxes feed into your 2026 Illinois credit calculation.
Does Itemizing Still Make Sense?
The federal SALT deduction only helps you if your total itemized deductions exceed the standard deduction. For 2026, the standard deduction is $32,200 for married couples filing jointly, $16,100 for single filers, and $24,150 for heads of household.2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Your SALT payments, mortgage interest, charitable contributions, and other itemizable expenses have to clear that bar together.
With the SALT cap at $40,000, far more Illinois homeowners will clear it. A married couple paying $15,000 in property taxes, $5,000 in state income taxes, and $14,000 in mortgage interest has $34,000 in itemized deductions, just above the joint standard deduction. Under the old $10,000 cap, that same couple would have reached only $24,000 and would have taken the standard deduction instead.
The Illinois credit is independent of this choice. You claim it on your state return whether you itemize federally or not. Even if you take the federal standard deduction, you should still claim the state credit.
How to Claim Both
Before you start, pull together your property tax bill (which carries your Property Index Number), the total you paid during the calendar year, and Form 1098 from your lender if your taxes go through escrow. The Property Index Number is the unique identifier for your parcel, printed on the tax bill, assessment notice, or deed.7Illinois Department of Revenue. 2025 IL-1040 Schedule ICR Instructions If you pay the county directly, use receipts or cancelled checks to verify the amount.
For the federal deduction, enter property taxes on Line 5b of Schedule A (Form 1040).8Internal Revenue Service. Instructions for Schedule A (Form 1040) (2025) Lines 5a through 5c together are what the SALT cap applies to. For the Illinois credit, complete Schedule ICR and attach it to Form IL-1040.7Illinois Department of Revenue. 2025 IL-1040 Schedule ICR Instructions Both returns can be filed electronically or on paper.
Keep your tax bills, proof of payment, and closing statements for at least three years. The IRS and the Illinois Department of Revenue can both request documentation, and the records are easier to produce when they are already in one place.