Missouri vs Illinois personal injury law.

Practical impact

The single largest practical difference. A crash on the wrong side of the river can be filed three years after the deadline runs on the other side. A case that's stale in Illinois may still be live in Missouri, and vice versa for an MO claim heading toward the IL deadline.

Practical impact

Both measured from the date of death, not the underlying injury. Both are shorter than the standard PI window in Missouri. Families often think they have the general 5-year MO window. They don't.

Practical impact

In Missouri, a plaintiff found 80% at fault still recovers 20% of damages. In Illinois, a plaintiff found more than 50% at fault recovers nothing. Mixed-liability cases (left-turn collisions, lane-change crashes, pedestrian-in-crosswalk-disputes) turn out very differently under the two regimes.

Practical impact

Both states allow full damages in standard PI cases. Missouri caps non-economic damages in medical malpractice ($481,250 base for non-catastrophic, $962,500 catastrophic; adjusts annually). Illinois had similar caps struck down as unconstitutional. Punitive-damages frameworks differ in each state.

Practical impact

In Missouri the question is not whether anti-stacking clauses are enforceable, it is which coverage you are stacking. UM is statutorily required, so the clause gives way. UIM is a matter of contract, so the clause usually holds. That single distinction can be the difference between one policy limit and three on a catastrophic case. There is also a wrinkle worth checking every time: under Krombach v. Mayflower Ins. Co., 827 S.W.2d 208 (Mo. banc 1992), if the policy's own definitions treat an underinsured motorist as a kind of uninsured motorist, the UM rule can reach the UIM limits too. That is a drafting accident in the carrier's paperwork, and it is found by reading the policy rather than by asking the adjuster. Never accept a carrier's first position on stacking without the declarations page and the full policy form.

Practical impact

Bars and restaurants get sued for over-service in both states, but Illinois plaintiffs have a lower factual bar to clear in exchange for a statutory damages cap. Missouri plaintiffs need stronger facts but face no statutory cap. Investigation strategy differs significantly.

Practical impact

Neither state has the blanket pre-suit notice requirement people expect. Illinois repealed its Tort Immunity Act notice sections in 1986; what remains is a one-year deadline to file suit that replaces the ordinary two years. Missouri's 90-day notice reaches only cities of 100,000 or more, and only defects in a bridge, boulevard, street, sidewalk, or thoroughfare, so it does not apply to counties or smaller municipalities. The trap is the Illinois one-year filing deadline, which is easy to miss while assuming two years.

Practical impact

Cases against government defendants are harder than private-party cases in both states. Illinois's framework is generally more defendant-favorable than Missouri's.

Practical impact

Both states allow pre-judgment interest in PI but the triggers and rates differ. On a case with significant delay between injury and resolution, interest can be a meaningful component of total recovery.

Practical impact

Both states allow recovery beyond policy limits when the carrier acts unreasonably. Illinois's 215 ILCS 5/155 attorney-fee shifting is one of the more plaintiff-friendly bad-faith regimes in the country.

Practical impact

Settlement math changes meaningfully between the two states. Illinois lien caps mean a higher percentage of gross settlement flows through to the client; Missouri liens can consume a larger share but are subject to lien-reduction negotiation.

Practical impact

In multi-defendant cases (chain-reaction crashes, premises cases with multiple owners), the allocation rules affect how much each defendant ultimately pays. Discovery strategy differs based on which defendants are likely to be high-percentage versus low-percentage fault.