This memo investigates two questions that pertain to extended foster care and social support. First, are there differences in the types and sources of social support between young people who remain in care past age 18 and young people who exit care? Second, among nonminor dependents, are there differences in the types and sources of social support between youth living in different placement types? To answer these questions, the authors analyzed data collected from CalYOUTH participants when they were 19 years old. This memo draws on findings from a more extensive peer-reviewed journal article published in a special issue of the Longitudinal and Life Course Studies (LLCS): International Journal (Okpych, Feng, Park, Torres-García, & Courtney, 2018). In the article, social support differences by placement type were also examined when participants were 17 years old.