Data from 18,437 children enrolled in the national evaluation of the Children's Mental Health Initiative between 1994 and 2005 were used to examine the evolution of patterns of risk among boys and girls across funding phases using multigroup latent class analysis. Consistent with previous research, this study identified four subgroups of children with similar patterns of child risk. Membership to these risk subgroups varied as a function of age and was associated with differences in impairment levels. Changes in the distribution of boys and girls in the risk classes suggest that, over time, an increasing proportion of boys have entered the system of care program with complex histories of risk. Information on children's exposure to child risk factors can aid policy makers, service providers, and clinicians in identifying children who may need more intensive services and tailoring services to their needs.