Revise laws relating to pharmacies, pharmacy benefit managers, and other entities

This bill revises Montana laws governing pharmacies, pharmacy benefit managers, and related entities to regulate how prescription drug costs are managed and audited. It directly affects pharmacies, pharmacy benefit managers, health insurers, and third-party payers by establishing clearer rules for reimbursement and audits. Key provisions prohibit certain audit practices, such as charging interest during audits, using statistical extrapolation to calculate penalties, or recouping funds for minor clerical errors unless actual financial harm occurs. The bill also defines important terms like "maximum allowable cost list" and "reference pricing" and sets requirements for drug inclusion on reimbursement lists, including mandates that drugs be FDA-rated and available from wholesalers. Additionally, it restricts how pharmacies can validate drug purchases for compliance purposes, allowing them to use purchase records without date or source limitations as long as state and federal laws are followed.