Although stratification scholars increasingly study the role of family background in shaping attainment across the entire life course, research has yet to establish whether the family characteristics that shape attainment early in the career are the same family characteristics that shape attainment late in the career. Applying an extended sibling correlation approach to brothers’ life cycle earnings and family income in the U.S. National Longitudinal Survey of Youth 1979, I document a near-perfect correlation in the family characteristics that affect attainment at early, mid, and late career stages. This result carries important theoretical implications for how stratification scholars conceptualize the impact of family background across the career. Family background appears to constitute a single dimension in determining attainment across the life course. Further analyses also suggest that the imperfect relationship between current and lifetime income is driven exclusively by within-family processes.