Abstract
Using U.S. Department of Education data, the current study examined changes in the rates of special education eligibility classifications. This was done to determine if classification substitution might be an explanation for increases in the number of students being found eligible for special education using the Autism criteria. Results reveal that as the rates of Autism have gone up, the rates of mental retardation (MR), emotional disturbance (ED), and specific learning disability (SLD) have gone down. From these data it was concluded that it is possible that the increased numbers of students found eligible for special education using Autism criteria, is at least in part a function of IEP teams being increasingly more willing and able to use autism criteria instead of MR, ED, and SLD criteria.