Medical Malpractice Laws in Missouri.

Non-economic damages for non-catastrophic injuries are capped at approximately $473,444 (2025), increasing annually at 1.7% from the original $400,000 base. Constitutional validity contested — the Missouri Supreme Court struck down caps in wrongful death med mal (Watts v. Cox, 2012), but the legislature re-enacted them.

Catastrophic injuries (quadriplegia, paraplegia, loss of 2+ limbs, significant permanent cognitive impairment, irreversible organ failure, significant vision loss) have a higher cap of approximately $828,529 (2025), from a $700,000 base. No cap on economic damages.

The plaintiff or attorney must file an affidavit within 90 days of filing the complaint, stating that a legally qualified healthcare provider has provided a written opinion that the defendant failed to use reasonable care and that failure caused the claimed damages. Court may extend for an additional 90 days for good cause. Failure to file results in dismissal.

Expert witnesses must be licensed in Missouri or another state, in the same profession as the defendant, and actively practicing (or within 5 years of retirement from) substantially the same specialty as the defendant.

Missouri follows the physician-based (professional) standard — the question is whether the physician disclosed what a reasonably prudent physician would disclose, not what a reasonable patient would want to know.