Prevalence of children with emotional or behavioral disorders (EBD) is a critical component in the discussion of underidentification of children served in special education. This discussion has previously focused almost exclusively on point prevalence or the number of children with EBD presumably needing services at any single point in time. Cumulative prevalence, on the other hand, is the number of children who have had EBD at some point in their lives before high school graduation. In the authors' review of both types of prevalence, they found that estimates of the latter far exceed those of the former, significantly highlighting the service gap that exists between prevalence estimates and special education identification. Even when point prevalence is limited just to children with moderate or severe disorder, special education identification in the emotional disturbance category appears restricted to less than the bottom tenth of all children in need. Implications for special education are discussed, including issues around underidentification, misidentification, underservice, and related issues concerning children with EBD. (Contains 2 tables.)