This chapter briefly reviews vexing sexual orientation and gender identity disparities in health and well-being. It focuses largely on sexual and gender minority (SGM) people in the West, specifically in the United States. The chapter also focuses on the role and meaning of stigma and minority stress in the lives of SGM youth, with attention to stigma at the societal or structural level and internalized stigma at the individual level. But stigma is also interpersonal; a large portion of research on SGM adolescents and young adults has focused on interpersonal and contextual sources of stigma or discrimination in their lives. Thus, the chapter considers developmental contexts and processes that shape the lives of SGM adolescents and young adults: their interpersonal, school and peer, and community and civic contexts and their health and well-being. It concludes with discussion of urgent issues of the health and rights of SGM people. (PsycInfo Database Record (c) 2022 APA, all rights reserved)