Revise laws related to prior authorization

This bill revises Montana laws governing prior authorization requirements for health insurance coverage. It primarily affects health insurance issuers, utilization review organizations, and patients by extending the validity of prior authorization certifications for chronic conditions to last as long as the condition itself. The legislation also prohibits prior authorization for certain prescriptions and updates definitions related to medical necessity, adverse determinations, and grievance processes. These changes aim to streamline administrative procedures and reduce barriers to accessing necessary healthcare services for individuals with ongoing medical needs.