In 1989, the delegate assembly of the Council for Exceptional Children began the process of developing standards of knowledge and skills for all beginning teachers of special education, including teachers of children who are deaf or hard of hearing. Now in its third major revision, these standards provide guidance to states' departments of education and to teacher preparation programs both nationally and internationally. This article provides a brief chronology of the process and presents a discussion of the most recent revalidation sequence. Two companion articles present the new standards for initial teacher preparation and advanced teacher preparation, including the evidence base in support of the standards' statements. (Contains 1 table and 4 figures.)