This article examines career choices using a dynamic structural model that nests a job search model within a human capital model of occupational and educational choices. Wage growth occurs in the model because workers move between firms and occupations as they search for suitable job matches and because workers endogenously accumulate firm and occupation specific human capital. Simulations performed using the estimated model reveal that both self-selection in occupational choices and mobility between firms account for a much larger share of total earnings and utility than the combined effects of firm and occupation specific human capital.