This observational study of 99 insured patients receiving an extended-release medication for opioid use disorder found meaningful reductions in healthcare utilization following treatment initiation, including fewer all-cause emergency department visits, fewer inpatient admissions, and shorter hospital stays. The findings suggest that extended-release formulations can improve system-level efficiency while supporting harm reduction, even among patients who continue intermittent opioid use. While financial barriers such as cost and insurance disruptions limited treatment continuity for some patients, the results align with prior clinical trial evidence and highlight the potential for extended-release medications to reduce strain on emergency and inpatient services, particularly when access and coverage barriers are addressed.