In Illinois, the Equalized Assessed Value is the figure your property tax bill is actually built on. It’s your local assessor’s assessed value, adjusted by a state multiplier so counties are treated consistently, and then reduced by any exemptions you qualify for. Whatever’s left, your taxable EAV, gets multiplied by the combined tax rates of every taxing district that covers your property to produce the dollar amount you owe.
The Three Steps That Produce Your EAV
Every Illinois property tax bill starts with the same sequence: assessed value, state equalization, exemptions.
Step one is the local assessor’s number. In all 101 counties outside Cook, the assessor takes the estimated fair market value and multiplies by one-third (33 1/3%) to produce the assessed value.1Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200-9-145 – Statutory Level of Assessment A $300,000 home receives an assessed value of roughly $100,000.
Step two is state equalization. Local assessors don’t always land on one-third exactly. Every year the Illinois Department of Revenue reviews each county’s overall assessment level and issues a multiplier. Counties assessing below one-third get a factor above 1.0000, pushing values up; counties assessing too high get a factor below 1.0000.2Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200-17-25 – Application of Final Equalization Factor A county whose aggregate assessments fall within 99% to 101% of the target is left alone with a factor of 1.0000.3Illinois.gov. 2025 Gallatin County Tentative Multiplier Announced
Assessed value times the equalization factor equals your EAV.4Illinois Department of Revenue. Publication 136 – Property Assessment and Equalization If your assessed value is $100,000 and the county factor is 1.05, your EAV is $105,000. Without this step, counties that systematically under-assess would shift costs onto counties that assess accurately.
Step three, exemptions, reduces the EAV to the taxable EAV. That’s the number the tax rates hit.
Why Cook County Numbers Look Different
Cook County doesn’t use the one-third rule. It runs a classification system: residential properties and apartment buildings are assessed at 10% of fair market value, and commercial and industrial property at 25%.5Cook County Assessor’s Office. Your Assessment Notice and Tax Bill The same $300,000 home starts with an assessed value of $30,000, not $100,000.
That gap is closed by equalization. Cook County’s factor runs well above 1.0000 to bring residential EAVs in line with the rest of the state, so homeowners there aren’t paying less simply because the starting percentage is lower. Cook County commercial property owners face the 25% level, more than double the residential rate.6Cook County Assessor’s Office. How Commercial Properties Are Valued
Exemptions That Reduce Your EAV
Illinois lets homeowners subtract fixed dollar amounts from their EAV before rates are applied. This is often where the biggest savings live, and several exemptions require you to apply.
General Homestead Exemption
If you own and occupy the property as your principal residence, you qualify. The maximum reduction is $10,000 in Cook County, $8,000 in counties bordering Cook, and $6,000 elsewhere.7Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200-15-175 – General Homestead Exemption The exemption technically equals the increase in EAV above the property’s 1977 EAV, capped at those amounts, so most homes get the full cap.
Senior Citizens Homestead Exemption
Homeowners aged 65 or older who occupy the home as a primary residence get an additional reduction: up to $8,000 in Cook County and contiguous counties, or $5,000 elsewhere.8Illinois Department of Revenue. Property Tax – Exemption Information This stacks on the General Homestead Exemption, so a qualifying senior in Cook County can see up to $18,000 taken off the EAV.
Senior Citizens Assessment Freeze
Separate from the flat-dollar senior exemption, the assessment freeze locks your EAV at the level from the year before you first qualified. If EAV was $80,000 when you turned 65 and rises to $95,000 three years later, you’re still taxed on $80,000. For the 2026 tax year, the maximum household income to qualify is $75,000 under Public Act 104-0452. You must reapply each year and meet the income test to keep it.
Homestead Exemption for Persons With Disabilities
A qualifying disability plus primary residence occupancy gets you a $2,000 annual reduction in EAV.9Justia Law. Illinois Code 35 ILCS 200-15-168 – Homestead Exemption for Persons With Disabilities Social Security disability benefits or an Illinois Person with a Disability Identification Card meets the eligibility standard.
Veterans Exemptions
The Returning Veterans’ Homestead Exemption provides a $5,000 EAV reduction for the tax year a veteran returns from active duty in an armed conflict.10Justia Law. Illinois Code 35 ILCS 200-15-167 – Returning Veterans Homestead Exemption
The Veterans with Disabilities Homestead Exemption is ongoing and scales with the service-connected disability rating from the U.S. Department of Veterans Affairs:
- 30 to 49% disability: $2,500 EAV reduction
- 50 to 69% disability: $5,000 EAV reduction
- 70% or greater: $250,000 EAV reduction, which zeroes out property taxes for most homes11Cook County Assessor’s Office. Veterans with Disabilities Exemption
Home Improvement Exemption
Remodel, add a room, or rebuild after a catastrophic event and the resulting increase in assessed value can be shielded for four years. The exemption covers up to $75,000 in fair cash value of the improvement, which converts to a maximum $25,000 reduction in assessed value.8Illinois Department of Revenue. Property Tax – Exemption Information Some counties apply it automatically; Cook County requires a separate application.
How Taxable EAV Becomes a Tax Bill
Once every property in a taxing district has a taxable EAV, local taxing bodies decide how much money they need for the year through a levy. Each school district, park district, municipality, library district, and other unit files its own. The county clerk divides each levy by the total taxable EAV of all property in that district to produce a tax rate.12Illinois Department of Revenue. PTAX-60 – Illinois Property Tax Rate and Levy Manual
Your bill is the sum of all overlapping district rates times your taxable EAV. If taxable EAV is $95,000 and the combined rate is 8%, the bill is $7,600. Most Illinois property sits inside a dozen or more overlapping districts, with school districts usually the largest share.
The Property Tax Extension Limitation Law caps how fast a district’s total levy can grow year to year. The annual limit is the lesser of 5% or the CPI increase for the prior calendar year.13Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200-18-185 – Extension Limitation For the 2025 levy year (taxes payable in 2026), CPI came in at 2.9%, so that’s the cap. PTELL limits the total dollars a district can collect, not the rate. If EAVs drop but the levy stays flat, the rate goes up to collect the same dollars. Voter-approved bond referenda and certain other categories are exempt, and PTELL only applies in counties that have adopted it, though most now have.
Challenging an EAV That Looks Too High
If your EAV seems inflated, you can contest it. The deadlines are short, and missing them forfeits the year.
The first stop is the county Board of Review. Outside Cook County, you have 30 calendar days after publication of the assessment list to file.14Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200-16-55 – Complaints Cook County residents get at least 20 days after publication of the notice.
Two grounds are available: overvaluation and unequal assessment (your property assessed higher than similar ones). Useful evidence includes a recent appraisal, comparable sales, and documentation of your property’s actual characteristics. A factual error, say, the assessor showing 2,400 square feet when the home is 2,000, can be enough on its own. A conversation with the township assessor before filing sometimes resolves things without a hearing.
If the Board of Review denies you, the next step is the Illinois Property Tax Appeal Board. You have 30 days from the Board of Review’s written decision.15Illinois Property Tax Appeal Board. Filing Your Appeal PTAB expects a completed form plus all supporting evidence up front, including a grid analysis of comparable sales or assessments. Thin evidence gets dismissed. Overvaluation must be proven by a preponderance of the evidence; unequal assessment carries a higher bar of clear and convincing evidence.
Reading the Numbers on Your Assessment Notice
Every number in this article appears in sequence on your annual assessment notice and tax bill. The notice shows the estimated fair market value, the assessed value (one-third of market value outside Cook, 10% inside Cook for residential), the equalization factor, the EAV, each exemption granted, and the taxable EAV after exemptions.5Cook County Assessor’s Office. Your Assessment Notice and Tax Bill The bill then lists each taxing district’s rate and the dollar amount levied against you.
Check every line. Errors in square footage, lot size, or property classification are common, and each inflates the EAV. If an exemption you qualify for is missing, contact the county assessor’s office before the appeal deadline. Several of the exemptions above are not applied automatically, and skipping the application means paying more than the law requires.