Research on the assimilation of childhood immigrants has shown that arrival in a new country at later stages of childhood development is negatively related to skill formation and adult economic well-being. This study examines the relationship between childhood immigrants’ age at arrival and economic assimilation by focusing on distributional variation in effects on wages and sorting across occupations and workplaces. I analyze Norwegian administrative panel data on siblings, which allows me to disentangle the effect of age at arrival on adult outcomes from all fixed family-level conditions and endowments shared by siblings. Results from sibling fixed-effects models, first, reveal progressively stronger adverse age-at-arrival effects throughout the wage distribution. Second, I show that older-arriving childhood immigrants sort into occupations with specific skill profiles (i.e., characterized by more physical and less language/communication, socioemotional, and math/logic skill requirements) and workplaces with lower paid, less educated, and more immigrant employees. Further, sorting by occupational skills and characteristics of workplace seem to matter more than formal education in mediating the observed age-at-arrival gradients in wage inequalities.