The longitudinal study in this article tested whether advantages in the career development of high school seniors resulted in better transition outcomes for these young adults 3 years after they graduated from high school. Enhanced career development in high school was significantly connected to more successful transitions into the adult roles of worker and learner and to greater satisfaction with one's life. Providing consistent and competent career development services to all students in high school is an essential task for professional school counselors. (Contains 1 table and 1 figure.)