Substance use disorder (SUD), including opioid use disorder (OUD), requires coordinated, evidence-based approaches across healthcare settings to improve patient outcomes and strengthen continuity of care. This series explores strategies for identifying and treating substance use disorder in both Emergency Department and perinatal care environments, highlighting opportunities for early intervention, overdose prevention, and initiation of treatment using medications for opioid use disorder (MOUD). . Through applied discussion and case-based examples, learners will explore patient-centered approaches that support engagement in treatment of individuals with substance use disorder across the continuum of care.