About 8,500 graduates of Wisconsin high schools and a randomly selected brother or sister have been followed from 1957 through the early 1990s. Data include multiple measures of social background, cognitive ability, schooling, and occupations held from career entry to midlife. The authors have analyzed occupational standing across the life course, using complementary measures of occupational education and occupational income. The analysis is based on structural equation models of sibling resemblance. The models estimate the effects of social background, cognitive ability, and schooling-both within and between families-across the life course of women and men. Across families, educational attainment levels are determined largely by cognitive ability and, to a lesser degree, by social background; family levels of occupational standing are determined largely by family education levels. Within families, cognitive ability also affects occupational standing primarily through schooling. Occupational inequalities and the effects of educational attainment on those inequalities both tend to decline across the life course.