Illinois uses modified comparative fault with 51% bar. Authority: 735 ILCS 5/2-1116.
The Illinois pattern jury instructions ask jurors to determine: (1) was the defendant negligent? (2) was the plaintiff negligent? (3) was each party\'s negligence a substantial factor in causing the injury? (4) what percentage of fault, totaling 100%, do you assign to each party?
The court applies the modified comparative fault (51% bar) formula to those percentages after the verdict form is returned.
Illinois's comparative-fault doctrine determines how much of a personal-injury verdict an injured plaintiff actually keeps. Two plaintiffs with identical $1,000,000 verdicts can walk away with wildly different recoveries depending on the fault percentages the jury assigns.
Under Illinois's 51% rule, the bright line sits at 51% plaintiff fault. A 50%-at-fault plaintiff retains a 50% recovery; a 51%-at-fault plaintiff recovers nothing. This is the most common modified-fault rule in the country.
Pre-trial settlement valuation and trial strategy in Illinois both turn on these numbers. Below: five scenarios at common verdict sizes and fault percentages, with the recovery a Illinois plaintiff would actually receive under the state\'s modified comparative fault (51% bar) rule.
| Verdict | Plaintiff fault | Net recovery | Reduction |
|---|---|---|---|
| $100,000 | 10% | $90,000 | $10,000 |
| $250,000 | 25% | $187,500 | $62,500 |
| $500,000 | 49% | $255,000 | $245,000 |
| $500,000 | 50% | $250,000 | $250,000 |
| $1,000,000 | 60% | $0 | $1,000,000 |
Worked example: a Illinois jury awards a plaintiff $500,000 in damages and finds the plaintiff 10% at fault. Under the state's modified comparative fault (51% bar) rule, the plaintiff actually recovers $90,000.
Worked example: a Illinois jury awards a plaintiff $500,000 in damages and finds the plaintiff 25% at fault. Under the state's modified comparative fault (51% bar) rule, the plaintiff actually recovers $187,500.
Practical illustration: an injured driver wins a $200,000 verdict in Illinois and the jury assigns 49% fault to them. Applying Illinois's modified comparative fault (51% bar) rule yields a net recovery of $255,000.
Worked example: a Illinois jury awards a plaintiff $500,000 in damages and finds the plaintiff 50% at fault. Under the state's modified comparative fault (51% bar) rule, the plaintiff actually recovers $250,000.
Practical illustration: an injured driver wins a $200,000 verdict in Illinois and the jury assigns 60% fault to them. Applying Illinois's modified comparative fault (51% bar) rule yields a net recovery of $0.
Illinois's rule changes how cases settle. In a state with a hard 50% bar, defense lawyers ramp up fault-allocation evidence , police reports, expert reconstruction, dashcam footage , because pushing the plaintiff over the threshold is worth the entire case. In pure-comparative states, both sides negotiate from a smoother slope.
Voir dire and jury instructions in Illinois comparative-fault cases shape outcomes as much as the underlying facts. Plaintiffs' counsel often spends opening arguments framing the plaintiff's actions as reasonable, knowing that even a moderate fault allocation can significantly reduce the verdict.
Illinois comparative-negligence rules only matter if you file on time. The state\'s personal-injury statute of limitations is 2 years from the date of injury (735 ILCS 5/13-202). Even an airtight liability case is dismissed with prejudice if the complaint is filed late.
Illinois applies modified comparative fault (51% bar). Illinois uses modified comparative fault with 51% bar.
Illinois bars recovery when the plaintiff is 51% or more at fault.
Illinois jurors are presented with a special verdict form asking them to assign fault percentages totaling 100% to each party (and any non-party at fault under joint-tortfeasor rules). The trial court then applies the comparative-fault formula to compute the final recovery.
Yes. Illinois juries can apportion fault among multiple defendants (and sometimes non-party tortfeasors). The treatment of joint and several liability , whether each defendant is liable only for their share or for the entire judgment if others are insolvent , varies by state statute.
Illinois courts vary on the "seat-belt defense." Some states allow evidence of non-use as a fault factor; others (by statute or judicial rule) exclude it. Plaintiffs\' counsel should consult current Illinois appellate decisions before deciding how to handle the issue at trial.
Generally yes , Illinois\'s comparative-fault rule applies across negligence claims, including medical malpractice. Some states adjust the framework for medmal cases (e.g., reducing the plaintiff-fault relevance because patients rarely contribute to their own injuries in the traditional sense), but the basic rule applies unless the statute carves out an exception.
In modified comparative fault (51% bar) Illinois, the bar threshold becomes the focal point of settlement: defendants negotiate harder near the threshold, plaintiffs accept reduced offers to avoid the bar.
Last verified against primary sources on 2026-05-16.