The findings show that developmental need is prevalent among young children in the child welfare system (CWS), independent of substantiation status. Multiple areas of development needs require the intervention of experts in child development, infant health, mental health, and education. Services are needed at an early age to all children in need in CWS to preempt these children’s need for extensive future developmental and educational services. Twelve percent of children had an Individualized Family Service Plan (IFSP), a proxy and marker of early intervention services through Part C of the Individuals With Disabilities Education Act of 1990. Part C services are intended to enhance the development of infants and toddlers with disabilities and minimize infants’ potential for developmental delay. The study found that 35.2 percent of children aged 1 to 3 years involved in CWS investigations were in need of Part C services at baseline. Caregivers and caseworkers reported, however, that only a minority of these children in need were receiving the IFSPs (12.7 percent) to which they were entitled under federal law. The need among children with substantiated cases did not exceed those of children in unsubstantiated cases in followup periods across 5-6 years. At baseline, children with unsubstantiated cases were more likely than those in substantiated cases to need early intervention services, suggesting that research is needed on the effects of environmental characteristics among children with substantiated cases. The study recommends further research on children with different substantiation results. Data were obtained from a sample of 1,845 children aged 0-36 months at baseline who were involved in child maltreatment investigations as infants or toddlers and were part of the National Survey of Child and Adolescent Well-Being (NSCAW) child protective services sample. Figures, tables, and references