For the past two decades, infants and toddlers with disabilities have received early intervention services in the United States under successive federal legislative acts. A significant limitation in prior research has been the lack of information describing these children’s characteristics beyond exit from early intervention services. Information regarding this population’s abilities when they enter kindergarten has not been available. The purpose of this study was to explore patterns of functioning in kindergarten for children who received early intervention services through Part C of the Individuals with Disabilities Education Act (P.L. 108-446, 118 Stat. 2647). The study drew on data from the National Early Intervention Longitudinal Study (NEILS). Data for this study included ratings of skills and abilities for 1,521 children, on 56 items from teacher surveys and family interviews. The data was nationally representative of all children entering Part C in the years 1997 to 1998. Using a functional approach based on the conceptual model and classification system of the International Classification of Functioning, Disability, and Health for Children and Youth (ICF-CY), three factors of functioning were identified. These factors described children’s functioning in mobility and self-care; behavioral and social functioning; and learning and applying knowledge. Cluster analysis was used to identify clusters of children with similar profiles of functioning on the three factors. Results indicated five distinct clusters of children with varying functioning in skills and abilities. Children in clusters were described in terms of children’s socio-demographic characteristics, description of disability at entry to Part C, and Individualized Education Program (IEP) status in kindergarten. The study provides evidence of the variability in Part C recipients’ functioning in kindergarten. The profiles raise questions about the experiences and characteristics of children in differentiated clusters, with implications for functioning and IEP status in kindergarten. The study also reinforces the utility of the ICF-CY as a universal taxonomy to describe dimensions of functioning, health, and disability. The study further suggests the importance of capturing precise estimates of functioning in universally defined domains, and communicating findings using a common language which is meaningful to professionals across disciplines.