The law is not the same on both sides of the river.
When the Mississippi separates the courthouse from your case, the rules change. Different fault doctrines. Different deadlines. Different caps. Different procedures. This page is the side-by-side guide.
At a glance
Five differences that change cases.
Fault doctrine
Missouri
Pure comparative fault
Illinois
Modified, 50% bar
PI statute of limitations
Missouri
5 years
Illinois
2 years
Wrongful death SOL
Missouri
3 years
Illinois
2 years
Damages caps
Missouri
Non-economic capped (med-mal)
Illinois
Mostly uncapped
Drunk driving
Missouri
DWI under § 577.010
Illinois
DUI under 625 ILCS 5/11-501
Implied-consent window
Missouri
15 days for license hearing
Illinois
46 days for SSS hearing
Comparative fault.
The rule that decides what happens when both drivers contributed to a wreck.
Missouri
Pure comparative fault
You can recover even if you were 99% at fault. Your award gets reduced by your share of fault, but you don't lose the right to recover. Mo. Rev. Stat. § 537.765.
Example: You were rear-ended but partly distracted. A jury finds you 25% at fault on $100,000 in damages. You collect $75,000.
Illinois
Modified comparative fault, 50% bar
If you are more than 50% at fault, you recover nothing. At 50% or less, your award is reduced by your share. 735 ILCS 5/2-1116.
Example: A jury finds you 51% at fault on $100,000 in damages. You collect zero. Same facts, MO side, you collect $49,000.
Statutes of limitations.
Miss the deadline, lose the case. The Mississippi River is a more dangerous fault line for SOL than most clients realize.
Full statute-of-limitations chartPersonal injury (negligence)
Mo. Rev. Stat. § 516.120; 735 ILCS 5/13-202
MO
5 years
IL
2 years
Wrongful death
Mo. Rev. Stat. § 537.100; 740 ILCS 180/2
MO
3 years
IL
2 years
Medical malpractice
Mo. Rev. Stat. § 516.105; 735 ILCS 5/13-212
MO
2 years (with exceptions)
IL
2 years (4-year statute of repose)
Product liability
Mo. Rev. Stat. § 516.120; 735 ILCS 5/13-202
MO
5 years
IL
2 years
Workers' compensation
Mo. Rev. Stat. § 287.430; 820 ILCS 305/6(d)
MO
2 years (or 3 if no report filed)
IL
3 years (or 2 from last payment)
Claims against a government entity
Mo. Rev. Stat. § 537.600 et seq.; 745 ILCS 10/8-101
MO
Notice within 90 days
IL
Notice within 1 year
Breach of written contract
Mo. Rev. Stat. § 516.110; 735 ILCS 5/13-206
MO
10 years
IL
10 years
What you can recover.
The same injury can be worth significantly different amounts depending on which side of the river you sue from.
Missouri
Capped in medical malpractice
General PI: no statutory cap on non-economic damages. Medical malpractice: non-economic damages capped at $487,000 (catastrophic) or $487,000 / $828,000 indexed for inflation per the 2015 amendments. Punitive damages capped at the greater of $500,000 or 5x compensatory.
Mo. Rev. Stat. § 538.210, § 510.265.
Illinois
Largely uncapped
The Illinois Supreme Court struck down medical malpractice caps in 2010 (LeBron v. Gottlieb). General PI non-economic damages remain uncapped. Punitive damages are not available in medical malpractice and wrongful death actions.
735 ILCS 5/2-1115; LeBron v. Gottlieb Mem'l Hosp., 237 Ill. 2d 217 (2010).
DWI vs DUI.
Same kind of charge, different procedural worlds. The administrative side moves faster than most defendants realize, on both sides.
Full DWI / DUI defense overviewMissouri (DWI)
Mo. Rev. Stat. § 577.010
Charged as Driving While Intoxicated. Standard adult limit 0.08% BAC. Administrative license suspension separate from criminal case. You have 15 days from arrest to request the administrative hearing or you lose the right to contest the suspension.
First-offense paths include SIS (Suspended Imposition of Sentence) and possibly a DWI court diversion program.
Illinois (DUI)
625 ILCS 5/11-501
Charged as Driving Under the Influence. Standard adult limit 0.08% BAC. Statutory Summary Suspension is automatic. You have 46 days from notice to file a Petition to Rescind or the suspension takes effect. Refusal triggers a 1-year suspension on a first offense.
First-offense paths include Court Supervision (no conviction enters) and Monitoring Device Driving Permit (MDDP).
The courts that matter.
Knowing the courthouse, the prosecutor, and the local practice often matters more than knowing the statute.
Missouri side
21st Circuit (St. Louis County) · 22nd (City) · 11th (St. Charles) · 23rd (Jefferson) · 20th (Franklin)
St. Louis County and City are constitutionally separate jurisdictions, with separate courts, prosecutors, and police. Each county has its own circuit court for felonies and serious civil matters; municipal courts handle ordinance violations and lower-level traffic.
The Carnahan Courthouse (City) and Buzz Westfall Courthouse (Clayton) operate independently.
Illinois side
20th Circuit (St. Clair, Monroe) · 3rd Circuit (Madison)
Madison County is nationally known for its civil docket. St. Clair County hosts the 20th Circuit in Belleville. Both counties have specific local rules, and the Illinois Supreme Court Rules apply uniformly across the state.
Edwardsville (Madison) and Belleville (St. Clair) are the principal courthouses for the Metro East.
What this means for your case
The wrong jurisdictional call costs cases.
If you were rear-ended on the Poplar Street Bridge headed east, your case is governed by Illinois law (modified comparative fault, 2-year SOL). Headed west, Missouri law (pure comparative fault, 5-year SOL).
If your DWI happened in Belleville, you have 46 days to challenge your license suspension. If it happened in Clayton, you have 15. Same fact pattern, three times the cushion on one side and almost none on the other.
If you got hurt at work and the injury straddled state lines (delivery driver, truck driver, contractor working in both states), there's often a choice of forum. Picking the right one matters.
Most St. Louis firms are licensed in only one of these two states, so they steer you toward the law they know. We are working from both sides. The choice gets made on the facts, not on the firm's roster.
This page is general information about Missouri and Illinois law as of the date of publication. It is not legal advice. Statutes and case law change. Specific outcomes depend on the facts of each case. Consult a licensed attorney about your situation.
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