As the Council for Children with Behavior Disorders(CCBD) celebrates its 50th anniversary, it seems like a good time to take stock of our field (Peck et al.,2011). There is probably no more fundamental way to do so than an analysis of prevalence; that is, how many school-age children actually have an emotional or behavior disorder (EBD)? We do know our identification rate, or the percentage of school children actually identified and served in the special education category of emotional disturbance (ED), which is slightly less than 1% of children enrolled in school (U.S. Department of Education, 2007). Prevalence, on the other hand, is not an object of much systematic study by special educators. Most prevalence studies are authored by psychiatrists or psychologists using primarily psychiatric diagnostic criteria to define what constitutes an emotional or behavior disorder (American Psychiatric Association, 2000). As we shall point out below, there are unfortunately far more children with moderate or severe EBD defined in this way than ever make it into special education. (Contains 1 table.)