Special education outcomes were evaluated for 3,608 children (2,513 males) with a preschool history of developmental disability. Sixty-six percent of the children had an identified disability in fourth grade. The percentage of children with a disability at outcome varied across preschool disability categories from 54% to 96%. The consistency of classification at preschool and outcome was relatively high for children with trainable mental handicap/profound mental handicap (TMH/PMH), emotional handicap/severe emotional disturbance (EH/SED), specific learning disability (SLD), and autism (AT) and lower for children with educable mental handicap (EMH), speech and/or language impairment (SI/LI), and developmental delay (DD). Understanding the nature and course of developmental disabilities can inform early intervention services, service planning, and resource management. (Contains 1 table and 1 figure.)