Committee hears bill to restore pre-2023 medical‑malpractice standard following Montana Supreme Court ruling

The House Business and Labor Committee heard testimony on House Bill 342, introduced by Representative Bill Mercer (House District 52, Billings), a measure that would codify Montana’s longstanding pattern jury instruction for medical‑malpractice cases and narrow the use of a proportionate‑risk jury instruction introduced by the Montana Supreme Court in 2023 in Kamen v. Glacier Eye Clinic.

Supporters told the committee the bill would restore a reasonableness‑based standard of care determined by medical experts rather than allow juries to apply a “proportionate duty” instruction that, they said, can cause juries to weigh a single catastrophic risk above competing clinical judgments.

Representative Bill Mercer, sponsor of the bill, told the committee the measure “is designed to say we are ... want to codify the standard of care that was in place before this Cayman decision.” Mercer said the bill…