The present study explored whether there were systematic differences in patterns of risk and protective factors among children attending Head Start. As well as whether children characterized by these patterns of risk and protective factors respond differently to the Incredible Years-Teacher Classroom Management (IY-TCM) program. Participants, drawn from the national Head Start CARES study, included 1037 4-year-old children. Groups of Head Start centers were randomly assigned to receive IY-TCM or continue with Head Start as usual. Children were assessed in the fall and the spring of the same academic year through parent report, teacher report, and direct child assessments. Latent Class Analysis (LCA) revealed five latent classes based on child, parent, and home risk factors. Within two of the latent classes, children in IY-TCM classrooms demonstrated positive responses to IY-TCM compared to those in the Head Start as usual classrooms. The results of this study expand on existing evidence of which children IY-TCM is most effective for. (author abstract)