A retrospective cohort study was conducted to identify child, maternal, family, and community factors associated with rate of developmental disability among children enrolled in the California Early Start Program. The cohort included 8,987 children considered at high risk for developmental disability due to medical risks and/or developmental delay. Analyses examined risk factors within a system hierarchy; levels included child's condition and qualifying risk factors, maternal characteristics, family qualities, and risk scores for residential county. Each level had factors predictive of developmental disability. Age at entry into the Early Start Program was the strongest determinant of outcome. Age at entry interacting with gender and developmental delays in physical, communication, and social/emotional developmental areas were strongly related to a shorter time to disability.