This white paper begins by describing recent theory and research on positive development, particularly as it applies to older adolescents and young or â€oeemerging” adults with serious mental health conditions. The next sections of the paper describe a series of empirically-supported and promising programs that are specifically designed to serve highly vulnerable populations of transition-age young people with serious mental health conditions, such as those who are homeless and those who are transitioning out of the juvenile justice system. Throughout these sections, we describe how the approaches taken in these programs are connected to central themes in the research and theory on positive development during late adolescence and early adulthood. Finally, we review some questions and implications raised by considering programs and interventions from a positive development perspective. [The material in this publication has been incorporated into a chapter in: M.L. Wehmeyer & K.W. Webb (Eds.), "Handbook of Adolescent Transition Education for Youth with Disabilities." (2012) London, UK: Routledge (ED528526).]