AbstractOBJECTIVE: The purpose of this work was to examine factors related to perceived impact of early intervention on children with disabilities and their families.METHODS: A nationally representative sample of approximately 2100 parents completed a 40-minute telephone interview near their child's third birthday. Structural equation modeling examined the relationships between 3 support variables (quality of child services, quality of family services, and family/community support) and 2 outcomes at 36 months (impact on child and impact on family) and determined whether these relationships were mediated by 2 perceptual variables (optimism and confidence in parenting) or moderated by 5 demographic variables (poverty, maternal education, ethnicity, age of initial Individual Family Service Plan, and health at 36 months).RESULTS: Perceived impact of early intervention on both child and family were significantly related to each other. The quality of child services was related to impact on the child but not on the family. The quality of family services was related to both child and family impact. Informal support was not related to perceived impact on children or families but was strongly related to confidence in parenting and optimism. Neither optimism nor confidence in parenting mediated the relationships between services or supports and perceived impact. Minority families and families of children with poor health reported lower quality of services, but these characteristics did not moderate the relationships between services and perceived impact on the child. However, both poverty status and minority status were associated with perceptions of impact on the family.CONCLUSIONS: Findings reinforce the role of high-quality services in maximizing perceived impact. They also highlight the important role of informal support in promoting optimism and confidence in parenting. Poverty status, minority status, and poor health of the child are salient factors in predicting lower perceived quality of and benefit from services.