Exploration and identity formation are primary developmental tasks during adolescence and the transition to adulthood. Yet little is known about occupational identity formation and growth during this period of life. In this chapter, the authors describe their ongoing research on this topic. First, they present their findings on the ontogeny of the complexity of career identities. Then they discuss their findings regarding the relationship between early career identity formation and psychological well-being at ages nineteen and twenty-one. (Contains 3 figures and 2 tables.)