According to the most recent ranking of impact factors (from June 2010) in Journal Citation Reports, the American Journal on Intellectual and Developmental Disabilities (formerly the American Journal on Mental Retardation) is ranked No. 2 in “Special Education” and No. 2 in “Rehabilitation.” The premier journal in its field for more than 115 years, AJIDD publishes expert contributions on the treatment and prevention of intellectual disabilities. The Journal is an essential reference for researchers in the biological and health sciences, and a crucial addition to human services libraries.