Illinois diminished value claims: what the law says
In Illinois you can claim diminished value from the at-fault driver: the repair cost plus the drop in value that remains after the repair. Your own collision policy generally won't pay it. You have five years to sue.
Written by Todd Whittington, Editor·Last reviewed Verified 2026-10-18
The short answer
Claim from the at-fault driver's insurer
Yes. You can claim the lost value from the at-fault driver's insurer.
Claim from your own insurer
No. Your own policy doesn't pay diminished value when the car is properly repaired.
Deadline to sue
5 years from the crash to sue for damage to your car
If you were partly at fault
Your claim is cut by your share of the blame, and you get nothing if you were more than half at fault.
State insurance department guidance
We found no diminished value guidance on the state insurance regulator's site.
Claiming from the other driver's insurer
Illinois's pattern jury instructions measure damage to repaired property as the repair cost plus the difference between its value right before the crash and its value after the repair. The total is capped at the before-and-after-crash value difference. An Illinois appeals court upheld this for a car as far back as 1929.
“The reasonable expense of necessary repairs to the property which was damaged plus the difference between the fair market value of the property immediately before the occurrence and its fair market value after it is repaired.” — Illinois Pattern Jury Instructions (Civil) 30.10 and 30.12; Welter v. Schell, 252 Ill. App. 586 (1st Dist. 1929)
Claiming from your own insurer
In Sims v. Allstate (2006), an Illinois appeals court held that a standard "repair or replace with like kind and quality" policy doesn't pay a repaired car's loss in market value. One judge disagreed, and a policy with different wording could be read differently.
“does not require Allstate to compensate its insured for a repaired vehicle's loss in market value due to the fact that it suffered damage” — Sims v. Allstate Ins. Co., 365 Ill. App. 3d 997 (5th Dist. 2006)
The deadline
You have five years to sue over injury to property, real or personal.
“or to recover damages for an injury done to property, real or personal, ... shall be commenced within 5 years next after the cause of action accrued” — 735 ILCS 5/13-205
If you were partly at fault
Modified comparative fault (51% bar). You're barred only if your fault was more than 50%. Otherwise your claim is cut by your share.
“the plaintiff shall be barred from recovering damages if the trier of fact finds that the contributory fault on the part of the plaintiff is more than 50%” — 735 ILCS 5/2-1116
What this means when you're deciding
Not your fault? Ask the at-fault driver's insurer in writing with the repair invoice and proof of the remaining loss.
Your own insurer generally won't pay under a standard collision policy.
Partly at fault? Up to 50%, cut by your share; above that, nothing.
Deadline: five years to sue. Run your numbers through the diminished value calculator first. If the typical appraisal midpoint is under $500, it is rarely worth chasing.
Is a claim worth it on your car?
The calculator runs the insurer's formula on your car, shows what appraisals usually find, and tells you whether to skip it, ask yourself, or pay for an appraisal.
Insurance department guidance: none found. idoi.illinois.gov site search for 'diminished value' returned no results; six IDOI auto consumer pages and 50 Ill. Adm. Code 919.80 checked; site-restricted web search found nothing.
We read every cited source on October 18, 2026. We cite statutes and court decisions, not law-firm or appraiser summaries. Anything we could not check against a primary source is marked "Not verified".