Developmental Disabilities Institute, also known as DDI, is a nonprofit agency that serves children and adults with autistic and developmental disorders. It has more than 25 residential and day habilitation sites. The institute offers starting early, children s day and young autism programs. Developmental Disabilities Institute operates an adult day services division that also maintains day treatment, family support services and career development departments. It provides family support and adult case management services. The institute also offers respite care solutions. Developmental Disabilities Institute provides after-school programs. In addition, it offers pediatric and adult medical care services. The institute has an early childhood direction center. Founded in 1961, Developmental Disabilities Institute serves patients in Nassau and Suffolk counties in New York.