At the intersection of college and work is a complex transition that graduates face every day. Lower levels of college to career transition self-efficacy (CTSE) and lower levels of perceived adulthood may cause a more difficult transition. In this mixed-method study we sought to better understand the relationships among perceived adulthood, CTSE, and the college to career transition. Participants were 1,220 graduates from colleges and universities in Pennsylvania. The findings suggest that a more fully developed sense of adulthood is a predictor of CTSE. Specific practices institutions can implement to support graduates are shared.