Illinois Car Accident Laws

Illinois is a fairly standard modified-comparative-negligence, at-fault state — the detail most likely to trip people up is that the injury deadline and the property-damage deadline are genuinely different lengths.

People often assume one deadline covers everything about their accident. In Illinois, your injury claim and your vehicle damage claim run on different clocks entirely.

Statute of limitations: 2 years (5 for property damage)

Under 735 ILCS 5/13-202, you generally have two years from the date of the accident to file a personal injury lawsuit. Property damage to your vehicle has a separate, much longer deadline: five years (735 ILCS 5/13-205). Claims against a government entity are shorter still — generally one year (745 ILCS 10/8-101).

Fault rule: modified comparative negligence, 51% bar

Under 735 ILCS 5/2-1116, you can recover damages if you're found 50% at fault or less, reduced by your percentage of fault. At 51% or more, you recover nothing.

Insurance: at-fault system, 25/50/20 minimum

Illinois is an at-fault state. Minimum liability limits are 25/50/20: $25,000 per person and $50,000 per accident for bodily injury, plus $20,000 for property damage (625 ILCS 5/7-601). Uninsured motorist (UM) coverage is mandatory in Illinois, alongside the standard liability requirement.

How this plays out in a real claim

Take an intersection collision where fault is genuinely disputed. If an insurer or court assigns you 40% of the blame, Illinois's rule still lets you recover 60% of your damages, and even at exactly 50% you still recover half. But at 51% or more, the claim is barred entirely — not reduced, eliminated. That one-point difference between 50% and 51% is exactly why insurers have a real incentive to push a borderline case just over the line rather than simply discount what they pay.

A mistake worth avoiding in Illinois

Because a single percentage point at the 51% threshold can be the entire difference between a reduced payout and nothing at all, careless statements at the scene or to an adjuster carry more weight here than in a pure comparative state. Avoid speculating about fault, even casually, until the full picture — police report, witnesses, any available footage — is in front of you.

If a government vehicle or agency was involved

Claims against the State of Illinois itself go through the Illinois Court of Claims, not the regular court system, under the Court of Claims Act. You must file a written notice with both the Illinois Attorney General and the Clerk of the Court of Claims within one year of the accident. Claims against local governments — a city, county, or transit agency — are handled separately under the Local Governmental and Governmental Employees Tort Immunity Act, which carries its own, generally shorter, notice requirements.

If the crash resulted in a death

Illinois gives two years from the date of death for a wrongful death claim (740 ILCS 180), filed by the estate's personal representative for the benefit of the surviving spouse and next of kin, with the court dividing any recovery based on each beneficiary's actual dependence on the deceased rather than a fixed split. Illinois is also unusual in now allowing punitive damages in a wrongful death claim itself (since an August 2023 amendment) where the conduct was malicious or reckless — though not against government or healthcare defendants.

Uninsured/underinsured motorist coverage

Illinois requires uninsured motorist (UM) coverage on every auto policy at a minimum of $25,000 per person/$50,000 per accident (215 ILCS 5/143a) — you can't waive it below that floor. Underinsured motorist (UIM) coverage works differently here: it isn't separately mandated, but it's automatically triggered at the same amount the moment you buy UM limits above the state minimum, so raising your UM coverage brings UIM along with it. Most Illinois policies also carry an anti-stacking clause, meaning you generally can't combine limits across multiple insured vehicles the way you can in some other states — it's worth checking your declarations page specifically for this.

Beyond the deadline and the fault rule

The statute of limitations and the fault rule above decide whether you have a claim and how much of it survives — they don't decide what the claim is actually worth, or whether it's worth handling yourself. For that, see our guides on what affects a settlement, who pays your medical bills while a claim is pending, and whether Illinois law makes a lawyer worth it for your specific situation.

When it's worth talking to someone

With a firm 51% cutoff and two different deadlines running in parallel, it's easy to lose track of exactly where you stand. A free, no-obligation conversation can clarify both.