Understanding Grave Disability, presented by Elizabeth Bromley, MD, PhD, reviews the concepts that inform decision-making about whether an individual meets criteria for grave disability. The course briefly addresses the history and intent of the Lanterman-Petris-Short Act and the development of community-based mental health treatment. The course reviews the kinds of scenarios in homeless outreach that can lead a team or outreach specialist to consider whether an individual is gravely disabled. It discusses strategies to assess for grave disability and to confirm or disconfirm whether grave disability is an appropriate determination. The course is intended for any homeless outreach worker (i.e., clinicians and non-clinicians) and intends to provide all outreach team members with the foundational concepts necessary to participate in team deliberation about options for vulnerable clients experiencing homelessness.