This study reports on the developmental functioning levels of children from birth through age 2 in early intervention services and children ages 3-5 in early childhood special education services at the time of entry into services, using data from the Oregon Early Childhood Assessment System. The assessment system contains data on the assessed developmental functioning levels of children based on the 16 Oregon early childhood foundation areas and the three U.S. Office of Special Education Programs federal reporting child outcome areas. The study analyzes developmental functioning data and key demographic variables (primary disability, gender, race/ethnicity, and primary home language) for the entire population of children in early intervention and early childhood special education services who received services over a 13-month period during 2006/07. The study results show the percentage of children in early intervention and early childhood special education services assessed as functioning below age-expected skill levels on skills assessments using age-related criteria embedded in the Oregon Early Childhood Assessment System database. With few exceptions, the developmental skills that were most often assessed as functioning below age-expected skill levels among children across all demographic subgroups were those important to school readiness in literacy and mathematics. Appended are: (1) The Oregon Early Childhood Assessment System; (2) Research on early intervention and early childhood special education services; and (3) Study methods and limitations. (Contains 16 tables and 1 box.)