A complete guide to Missouri’s pure comparative fault system — the rules for allocating fault, reducing damages, apportioning liability among multiple defendants, and the strategic implications for plaintiff and defense counsel
Missouri Injury & Insurance Law | missouriinjuryandinsurancelaw.com
Introduction
Missouri adopted a pure comparative fault system in 1983, replacing the harsh common law rule of contributory negligence that had barred recovery entirely whenever the plaintiff bore any share of fault for the injury. Under Missouri’s pure comparative fault system, a plaintiff’s own negligence reduces but does not eliminate recovery — even a plaintiff who is ninety-nine percent at fault recovers one percent of the damages.
Comparative fault is not merely a damages adjustment mechanism. It is a comprehensive framework that governs how fault is allocated among all parties and non-parties whose negligence contributed to the plaintiff’s injury, how liability for damages is apportioned among multiple defendants, and how the jury’s fault allocations translate into actual dollar recoveries. Understanding this framework in full is essential to evaluating cases, structuring settlements, and trying cases to verdict.
This post provides a complete treatment of Missouri’s comparative fault system: its history and governing authority, the rules for allocating and reducing damages, the modified joint and several liability statute, fault allocation to non-parties, the role of the jury, and the strategic implications for both plaintiff and defense practice.
From Contributory Negligence to Pure Comparative Fault
Before 1983, Missouri followed the common law rule of contributory negligence. Under that rule, any negligence by the plaintiff that contributed to the injury barred recovery entirely, regardless of how minor the plaintiff’s fault was compared to the defendant’s. A plaintiff who was one percent at fault and the defendant ninety-nine percent at fault recovered nothing. The rule was universally criticized as harsh, arbitrary, and inconsistent with common sense notions of fairness.
The Missouri Supreme Court abolished contributory negligence and adopted pure comparative fault in Gustafson v. Benda, 661 S.W.2d 11 (Mo. banc 1983). The Court in Gustafson acted in the exercise of its common law authority to develop Missouri tort law, explicitly choosing a pure comparative fault system over the modified (fifty percent) comparative fault systems adopted by many other states. Under Missouri’s pure system, there is no threshold percentage of fault above which a plaintiff is barred from recovery.
The legislature codified and extended comparative fault principles through subsequent statutes, most significantly the Tort Reform Act of 1987, which modified joint and several liability and established the framework for fault allocation to non-parties. The current statutory framework governing these issues is found primarily in § 537.067 R.S.Mo.
The Basic Rule: Pure Comparative Fault
Under Missouri’s pure comparative fault system, a plaintiff’s recovery is reduced in proportion to the plaintiff’s own percentage of fault. If the total damages are $1,000,000 and the plaintiff is found twenty percent at fault, the plaintiff recovers $800,000. If the plaintiff is found fifty percent at fault, the plaintiff recovers $500,000. If the plaintiff is found ninety-nine percent at fault, the plaintiff recovers $10,000.
| BASIC COMPARATIVE FAULT REDUCTIONFacts: Plaintiff suffers $500,000 in damages. Jury finds plaintiff 30% at fault and defendant 70% at fault.Result under Missouri pure comparative fault: Plaintiff recovers $350,000 (70% of $500,000). |
| HIGH PLAINTIFF FAULTFacts: Plaintiff suffers $1,000,000 in damages. Jury finds plaintiff 80% at fault and defendant 20% at fault.Result under Missouri pure comparative fault: Plaintiff recovers $200,000 (20% of $1,000,000). Missouri’s pure system allows recovery even at high plaintiff fault percentages. |
Comparative Fault Is an Affirmative Defense
Comparative fault is an affirmative defense that must be pleaded and proven by the defendant. A defendant who does not plead comparative fault waives it. Where the defendant properly raises comparative fault, the burden is on the defendant to produce evidence supporting the allocation of fault to the plaintiff. The plaintiff does not bear the burden of disproving contributory fault.
The MAI Instruction Framework
Missouri Approved Instruction 37.01 is the standard negligence verdict director that incorporates comparative fault. The jury is instructed to assess the percentage of fault attributable to each party and non-party, and the court then applies those percentages to the total damages to calculate each party’s recovery. The jury does not calculate dollar amounts after applying comparative fault percentages — it determines total damages and fault percentages separately, and the court applies the math.
Multiple Defendants: Modified Joint and Several Liability Under § 537.067
The most complex aspect of Missouri comparative fault law is its treatment of multiple defendants. Missouri has modified — but not eliminated — the common law doctrine of joint and several liability through § 537.067 R.S.Mo. Understanding this statute is critical to evaluating cases with multiple defendants and to structuring settlement strategy.
| § 537.067 R.S.Mo. — Joint and Several Liability of Defendants in Tort Actions1. In all tort actions for damages, if a defendant is found to bear fifty-one percent or more of fault, then such defendant shall be jointly and severally liable for the amount of the judgment rendered against the defendants. If a defendant is found to bear less than fifty-one percent of fault, then the defendant shall only be responsible for the percentage of the judgment for which the defendant is determined to be responsible by the trier of fact; except that, a party is responsible for the fault of another defendant or for payment of the proportionate share of another defendant if any of the following applies: (1) The other defendant was acting as an employee of the party; (2) The party’s liability for the fault of another person arises out of a duty created by the federal Employers’ Liability Act, 45 U.S.C. Section 51.2. The defendants shall only be severally liable for the percentage of punitive damages for which fault is attributed to such defendant by the trier of fact.3. In all tort actions, no party may disclose to the trier of fact the impact of this section. |
The Two-Track System
Section 537.067 creates a two-track liability system based on the defendant’s percentage of fault:
Defendants less than 51% at fault: Responsible only for their own proportionate percentage of the judgment. A defendant found 20% at fault pays only 20% of the judgment regardless of what other defendants pay or fail to pay. Two exceptions apply under 537.067.1: a defendant is also responsible for a co-defendant’s share if that co-defendant was the party’s employee, or if the party’s liability arises under the federal Employers’ Liability Act (FELA), 45 U.S.C. 51.
Defendants 51% or more at fault: Jointly and severally liable for the entire judgment rendered against all defendants — not just non-economic damages, but the full judgment including economic damages. A defendant found 60% at fault can be required to pay 100% of the judgment if other defendants cannot pay their shares. This is the key distinction from the pre-537.067 common law regime: the statute limits this exposure to defendants who are majority-fault actors.
Punitive damages — always several only: Section 537.067.2 provides that defendants are “only severally liable for the percentage of punitive damages for which fault is attributed to such defendant by the trier of fact.” There is no joint and several liability for punitive damages regardless of fault percentage. Each defendant pays only its own share of any punitive award.
The No-Disclosure Rule: 537.067.3
Section 537.067.3 contains a provision that is easily overlooked but critically important in practice: “In all tort actions, no party may disclose to the trier of fact the impact of this section.” This means the jury is not told that a defendant found more than 51% at fault will be jointly and severally liable for the full judgment, nor is the jury told that a defendant found less than 51% at fault will pay only its proportionate share. The jury allocates fault percentages without knowing the legal and financial consequences of those allocations. This prohibition shapes trial strategy significantly — counsel cannot argue the joint and several liability consequences to the jury, and the court will enforce this prohibition through in limine rulings.
| MULTIPLE DEFENDANTS: 537.067 IN ACTIONFacts: Jury awards $1,000,000 total damages. Defendant A is found 60% at fault; Defendant B is found 30% at fault; Plaintiff is found 10% at fault. Total judgment after plaintiff’s 10% reduction: $900,000.Result: Defendant A (60%, above 51%) is jointly and severally liable for the full $900,000 judgment. Defendant B (30%, below 51%) is liable only for $270,000 (30% of $900,000). If Defendant B is judgment-proof, Defendant A may be required to pay the entire $900,000. Note: punitive damages, if any, are always several only — each defendant pays only its proportionate share regardless of fault percentage. |
Contribution Among Defendants
Where one defendant pays more than their proportionate share of damages due to joint and several liability, that defendant has a right of contribution against other defendants for the excess. Missouri’s contribution statute, § 537.060 R.S.Mo., governs contribution rights among joint tortfeasors. The right of contribution does not affect the plaintiff’s recovery — it governs only the allocation of the payment burden among defendants.
Fault Allocation to Non-Parties
One of the most significant and strategically important aspects of Missouri comparative fault law is the ability to allocate fault to persons or entities who are not parties to the lawsuit. Section 537.067 permits the jury to consider the fault of non-parties when allocating total fault among all persons whose negligence contributed to the plaintiff’s injury.
Who Is a Non-Party for Fault Allocation Purposes
A non-party whose fault may be submitted to the jury includes: settling defendants who have been dismissed from the case, third parties who contributed to the injury but were never sued, immune parties such as employers in workers’ compensation cases, and in some circumstances the plaintiff’s own negligence in a separate capacity. The defendant seeking to allocate fault to a non-party must plead the non-party’s fault as an affirmative defense and produce sufficient evidence to support the allocation.
The Strategic Importance of Non-Party Fault
From the defense perspective, allocating fault to non-parties — sometimes called the “empty chair” defense — is a powerful tool for reducing the defendant’s liability. By attributing fault to a non-party who cannot defend themselves in the courtroom, the defendant can reduce its own percentage of fault and thereby reduce its damages obligation.
From the plaintiff’s perspective, non-party fault allocation is a significant threat. If the jury allocates substantial fault to a non-party who has no liability to the plaintiff — either because they settled, are immune, or were never sued — that fault allocation reduces the defendant’s obligation without providing the plaintiff any additional source of recovery. Plaintiff’s counsel must anticipate the non-party fault defense, challenge its evidentiary foundation, and prepare to counter it at trial.
Fault Allocation to Settling Defendants
A defendant who has settled with the plaintiff and been dismissed from the case may still have fault allocated against them by the remaining defendants. The settling defendant’s fault percentage reduces the non-settling defendants’ fault percentages but does not reduce the plaintiff’s recovery if the settlement amount was paid. Missouri’s pro tanto credit rule — § 537.060 R.S.Mo. — provides that a settlement by one tortfeasor reduces the claim against other tortfeasors by the amount paid in settlement, not by the settling defendant’s percentage of fault.
This interaction between fault allocation and settlement credit is one of the most complex areas of Missouri comparative fault law and requires careful analysis in any multi-defendant case involving partial settlements.
Plaintiff’s Own Fault: What Counts and How It Is Proven
Categories of Plaintiff Conduct That May Constitute Comparative Fault
Missouri courts have recognized a wide range of plaintiff conduct as potential comparative fault, including:
Failure to wear a seatbelt. Evidence that a plaintiff failed to wear a seatbelt is admissible for purposes of reducing damages attributable to the failure to use the seatbelt, subject to a statutory limitation under § 307.178 R.S.Mo. that caps the reduction at one percent of total damages.
Assumption of risk. In Missouri, assumption of risk is subsumed within the comparative fault framework rather than operating as a complete bar to recovery. A plaintiff who knowingly encounters a known risk may have fault allocated based on that assumption but does not forfeit the entire claim.
Contributory negligence in causing the accident. A plaintiff who failed to keep a proper lookout, failed to yield, was speeding, or otherwise contributed to the accident may have fault allocated for those acts.
Failure to mitigate damages. A plaintiff who unreasonably fails to seek medical treatment, follow medical advice, or otherwise minimize the consequences of the injury may have fault allocated for the resulting additional harm.
Proving Plaintiff’s Comparative Fault
The defendant bears the burden of producing evidence of the plaintiff’s comparative fault. This requires specific evidence — not merely argument — that the plaintiff acted in a manner that fell below the applicable standard of care and that this failure contributed to the injury or its severity. Where the only evidence of plaintiff’s fault is speculation or inference without an evidentiary foundation, the comparative fault instruction should not be submitted to the jury.
Missouri courts have held that a comparative fault instruction requires a submissible case on each element of negligence — the same elements that the plaintiff must prove against the defendant. The defendant must show that the plaintiff had a duty, breached it, and that the breach contributed to the injury. A generalized argument that the plaintiff “could have done something differently” is not sufficient without specific evidence supporting each element.
The Jury’s Role: Fault Allocation and the Verdict Form
The jury’s role in a Missouri comparative fault case is to: (1) determine whether each defendant and the plaintiff was negligent; (2) if negligence is found, determine the total damages; and (3) allocate fault percentages among all parties and submitted non-parties. The fault percentages must total one hundred percent.
The verdict form in a Missouri comparative fault case is structured to capture these separate determinations. The jury first answers liability questions for each party and non-party. If liability is established, the jury then determines total damages for each category without reducing for comparative fault. Finally, the jury fills in the fault percentage for each party and non-party. The court applies the percentages to the total damages to calculate the net recovery.
The One Hundred Percent Requirement
Missouri verdict forms require that all fault percentages sum to one hundred percent. This requirement has important practical implications: the jury cannot simply assign percentages to the parties before it without accounting for the total. In a case with a single defendant and the plaintiff, one hundred percent of the fault must be divided between them. In a multi-defendant case with non-parties, all allocated fault must total one hundred percent.
Where a jury returns a verdict in which fault percentages do not sum to one hundred percent, the trial court must address the deficiency before accepting the verdict. This is an area where careful jury instruction and verdict form design is critical.
Strategic Implications for Plaintiff’s Counsel
Anticipate and Address the Comparative Fault Defense
Plaintiff’s counsel must identify and address potential comparative fault issues before trial. Every aspect of the plaintiff’s conduct before, during, and after the accident should be reviewed for potential fault arguments. Weaknesses should be addressed in discovery, expert reports, and trial preparation. Jurors respond to parties who acknowledge their own role in events rather than appearing to deny obvious facts.
The Non-Party Fault Threat
In any case involving multiple possible tortfeasors, plaintiff’s counsel must evaluate whether the defendant will attempt to allocate fault to non-parties. If non-party fault is a realistic threat, counsel should consider: (1) joining all potential tortfeasors as defendants to prevent empty-chair allocations; (2) developing evidence that disproves the non-party’s fault or establishes that any non-party fault was not causally connected to the plaintiff’s injury; and (3) structuring settlement negotiations with settling defendants to minimize the impact of post-settlement fault allocations.
The Seatbelt Defense — Managing the One-Percent Cap
Where the seatbelt defense is likely, plaintiff’s counsel should ensure the jury understands the § 307.178 R.S.Mo. cap limiting any seatbelt-related fault reduction to one percent of total damages. Defense counsel will attempt to maximize the apparent importance of the seatbelt issue in the damages context; plaintiff’s counsel should counter by emphasizing the statutory limitation and focusing the jury on the primary cause of the accident and the full measure of the plaintiff’s injuries.
Economic vs. Non-Economic Damages Allocation
In high-damages cases with multiple defendants, the 537.067 threshold is the critical strategic number. A defendant found 51% or more at fault bears the risk of paying the entire judgment if co-defendants are insolvent or underinsured. A defendant found 50% or less at fault is protected from that exposure. The 51-percent line therefore has enormous practical significance: a one-percent difference in fault allocation can determine whether a defendant pays its proportionate share or the entire judgment. This shapes settlement negotiations, the decision whether to implead additional parties, and the development of the non-party fault defense. It is also important in dismissals. If you are going to settle with one or more parties, maybe time it close to trial leaving fewer or only one defendant to bring additional pressure.
Strategic Implications for Defense Counsel
Building the Comparative Fault Record
Defense counsel must build a complete record of plaintiff’s comparative fault through discovery, deposition, and expert testimony. This means documenting every aspect of the plaintiff’s conduct that could support a fault allocation: pre-accident behavior, compliance or non-compliance with applicable safety rules, the plaintiff’s own description of events, and any prior knowledge of risk. The comparative fault record must be developed early — it cannot be improvised at trial.
The Empty Chair Defense
Where there are non-parties whose negligence contributed to the plaintiff’s injury, defense counsel should develop the evidence needed to argue that to the jury. This requires identifying the non-party’s specific negligent act, establishing that it was causally connected to the injury, and presenting that evidence through competent witnesses and documents. A well-developed empty chair defense can substantially reduce the defendant’s fault percentage and corresponding liability. Be aware that a non-party’s fault cannot be apportioned so the defense will have to argue sole cause. This is something that plaintiff should address in a pre-trial motion and be prepared to object to such arguments.
Conclusion
Missouri’s pure comparative fault system is no longer a plaintiff-friendly system. The modified joint and several liability framework of § 537.067, the ability to argue the sole fault of non-parties, and the complexity of multi-defendant litigation create significant strategic challenges that require careful analysis in every case.
Mastering comparative fault means understanding not just the basic reduction formula but the full framework: how fault is allocated among parties, how the economic and non-economic damages distinction affects liability exposure, how settlement interacts with fault allocation, and how the jury instructions and verdict form shape the outcome. These issues arise in virtually every Missouri personal injury case and must be anticipated, planned for, and addressed at every stage of litigation.
This post is part of a foundational series on Missouri personal injury and insurance law. Related posts address the four elements of negligence, damages in personal injury cases, wrongful death, and the Missouri savings statute.
