This issue brief from the National LGBT Health Education Center at the Fenway Institute provides an overview of lesbian, gay, bisexual, and transgender health issues. The brief discusses LGBT demographics, terminology, and concepts and reviews LGBT health disparities across the life span. Clinicians and health care organizations will learn steps they can take to improve access to patient-centered care for their LGBT patients, including collecting data on sexual orientation and gender identity, creating a welcoming environment and providing interventions that respond to LGBT disparities.