State guide
Illinois property taxes (2026)
✓ Verified August 2026 against official county pages — 3 sources linked below.
County pages for Illinois are on the way — the statewide dates below apply everywhere, and county pages will add local rates, contacts, and exact appeal windows.
How Illinois property taxes work
Illinois property tax is local from top to bottom — the state Department of Revenue doesn't administer it. Township and county assessors set values, county Boards of Review hear appeals, county treasurers collect, and taxes are paid a year in arrears: the bills you pay in 2027 cover tax year 2026.
Outside Cook County, property is assessed at 33⅓% of market value. Cook County runs its own system — homes there are assessed at 10% of market value, and the county reassesses on a rolling three-year cycle, one third of the county at a time, township by township.
Appeals run through two layers: your assessor (in Cook, township-staggered windows announced through the year) and the county Board of Review. Windows are short — typically about 30 days from when your township or county's assessment notices publish — so the date to watch is the one on your own notice.
Bills come in two installments on county-set dates. Cook County's first installment (an estimated 55% of the prior year) is due in early March, with the second following in late summer — a date with a recent history of slipping. Other counties commonly bill in early summer and early fall.
When payments are due
Two installments a year, in arrears, on county-set dates — Cook's first installment lands in early March, most other counties bill summer and fall.
| Payment | Due | Delinquent after | Notes |
|---|---|---|---|
| First installment (2026 taxes) | — | — | County-set — Cook County's estimated first installment (55% of prior year) is due in early March 2027 |
| Second installment (2026 taxes) | — | — | County-set — Cook's lands in late summer/fall; most downstate counties bill June–September |
Exact dates can vary by county — use your county's page above for the dates on your bill.
How to appeal your assessment
The statewide rule: Appeal to your assessor and county Board of Review during your township or county's filing window — generally about 30 days from when the assessment notices publish
Cook County staggers windows by township across the year, and each property gets two shots annually — first with the Assessor, then with the Board of Review. Downstate, watch for your county's publication date; the 30-day clock runs from it.
- Find your windowCook County: check the Assessor's township schedule for when your township opens. Elsewhere: the appeal window follows your county's assessment publication — the notice or county site has the dates.
- Check your assessment against comparablesYour case is uniformity and market value: similar homes assessed lower, or sales showing your value is high. Assessor sites let you pull both.
- File with the assessor first (Cook)Cook's Assessor appeals are free and online; a reduction here ends the matter early. Downstate, some townships offer informal reviews.
- File with the Board of ReviewThe second (or downstate, main) stop — file during your window, free, with your evidence attached.
- Escalate if neededBoard of Review decisions can go to the state Property Tax Appeal Board or circuit court.
County pages have the exact local deadlines, forms, and filing links.
Statewide exemptions
| Exemption | What it's worth | Deadline |
|---|---|---|
| General Homestead Exemption | Cuts equalized assessed value by up to $10,000 in Cook County, $8,000 in the collar counties adjacent to Cook, and $6,000 elsewhere | Varies by county; automatic in some, application in others |
| Senior Citizens Homestead Exemption (65+) | An additional EAV cut of up to $8,000 in Cook and contiguous counties, $5,000 elsewhere | Annual application required in Cook County |
| Low-Income Senior Assessment Freeze | Freezes your equalized assessed value for homeowners 65+ with household income of $75,000 or less (2026 tax year; rising to $77,000 in 2027) | Annual application |
| Veterans & disability exemptions | Persons with disabilities: $2,000 EAV cut. Veterans with disabilities: $2,500 (30–50% rating), $5,000 (50–70%), or a full exemption on the first $250,000 of value at 70%+ | Annual application in most counties |
Reassessment
Cook County reassesses one third of the county each year on a rolling three-year cycle (the City of Chicago's turn comes in 2027). Downstate counties generally reassess on a four-year cycle with annual adjustments.
Value notices (Reassessment notice) usually mail in rolling (township by township in Cook).
Common questions
- When are property taxes due in Illinois?
- Two installments on county-set dates, paid a year behind. Cook County's first installment — an estimated 55% of last year's bill — is due in early March, with the second in late summer. Most other counties bill in early summer and early fall.
- How do I appeal my Illinois property assessment?
- File during your township or county's window — in Cook County, first with the Assessor (township-staggered, free, online), then with the Board of Review; downstate, with your county Board of Review within about 30 days of assessment publication. Uniformity evidence — similar homes assessed lower — wins cases here.
- Why is Cook County different?
- It runs its own classification system (homes assessed at 10% of market value versus 33⅓% downstate), reassesses on a rolling three-year township cycle, and staggers appeal windows across the year. If you're in Chicago, your next reassessment is the 2027 city triennial.
- What homestead exemptions does Illinois offer?
- The General Homestead Exemption ($10,000 EAV in Cook, $8,000 collar counties, $6,000 elsewhere), a senior exemption ($8,000/$5,000), a senior assessment freeze for household incomes up to $75,000 (2026), and substantial veteran-disability exemptions up to a full exemption on the first $250,000 of value.
- Why did my bill jump when my assessment didn't change?
- Illinois bills are rate-driven: local levies and the state equalization factor move your bill even in years your assessment holds still. And because taxes are paid in arrears, this year's bill reflects last year's values and levies.
Sources
Every fact on this page comes from an official page. Check them yourself:
- Illinois DOR — Property Tax Relief / Exemptions (PIO-74) — checked 2026-08-12
- Illinois DOR — Property Tax — checked 2026-08-12
- Cook County Assessor — assessment calendar and exemptions — checked 2026-08-12