Stigma toward individuals with substance use disorders (SUDs) remains a major barrier to effective care, particularly within the medical community where negative clinician attitudes can undermine trust, engagement, and treatment outcomes. Despite recognition of addiction as a chronic, treatable disease, patients are often viewed as less deserving of care than those with other conditions, with stigma compounded by factors such as marginalized identities, limited clinician education, and exposure to patients primarily during acute illness. This chapter explores the origins and impact of addiction stigma through clinical illustration and epidemiologic data, highlighting its role in treatment gaps and health disparities. It further examines contributors including the hidden curriculum, stigmatizing language, and misconceptions about addiction, and outlines strategies to address these issues, including enhanced education, person-first language, reflective practice, and system-level interventions. Reducing stigma is essential to improving therapeutic relationships, increasing access to care, and achieving better outcomes for individuals with SUDs.