More than 2 decades ago, Hallahan and Kauffman and others suggested a cross-categorical approach to teaching students identified with high-incidence disabilities (i.e., emotional-behavioral disabilities, learning disabilities, and mild intellectual disabilities) because their behavioral and academic characteristics were seen to be more similar than different. Since that time, more than 150 articles and other works have discussed and compared the characteristics of students across these high-incidence disability categories. This descriptive review examined 34 studies comparing various characteristics of students with high-incidence disabilities. The results indicate that students with emotional-behavioral disabilities, learning disabilities, and mild intellectual disabilities do not differ markedly in social adjustment, but do display considerably different cognitive and behavioral profiles. Implications for instruction and placement are discussed.