Each provincial medical regulatory authority (MRA) has its own set of guidelines and standards for OAT. The aim of this unified guideline is to standardize expectations for Canadian prescribers, but not to replace any adopted guidelines; rather, this guideline was developed to complement existing initiatives and to support prescribers with best practices and evidence. It serves as a “guideline of guidelines” by synthesizing key recommendations for treating and managing OUD from existing standards, guidelines, expert opinions and best practices across Canada.