What are the needs, perceptions and experiences of individuals with serious mental health conditions during the transition to adulthood? How can services best support them during this stage of life? These are the two interrelated questions that the articles in this special section address. The populations of focus in these articles are diverse: college students receiving educational supports, White and Latino young adults receiving employment supports, youth and young adults with justice system involvement, young adults with mood disorders, and service providers for youth in transition to adulthood in large urban behavioral health centers. The focus on diverse samples highlights some of the progress in the field. Questions about the needs of, and effective services for, individuals with serious mental health conditions as they transition into adulthood have moved from asking broad questions to including questions about more specific marginalized subgroups. As editors, we hope this special section provides readers with up-to-date literature syntheses and new knowledge, while also moving the field forward toward more research, more effective services for this age group, and services that will enhance their recovery and overall life outcomes.