The Administration on Developmental Disabilities sponsored a study of three of the state Developmental Disabilities (DD) Network programs: (1) State Councils on Developmental Disabilities, (2) Protection and Advocacy Agencies, and (3) University Centers for Excellence on Developmental Disabilities. This study, conducted by Westat, describes the achievements and accomplishments of the three DD Network programs on the lives of people with developmental disabilities and their families. The project was divided into two phases. Phase I (October 2005–September 2008) consisted of two activities: (1) the development of study tools for describing the DD Network programs accomplishments and achievements on people with developmental disabilities and their families; and (2) a pilot study to test the accuracy, feasibility, and utility of these tools. In the Phase II (October 2008–December 2011), the study was implemented on a sample of DD network programs using the tools designed in Phase I.