The Diagnostic and Evaluation (D&E) Team provides services including interdisciplinary evaluations, recommendations, and referrals. Services are available to persons, regardless of age, residing in Mississippi from a designated service area who might have a developmental disability.

Referrals can be made by parents or professionals by contacting the Jaycee Evaluation Center located on Ellisville State School's main campus. A Department of Mental Health Application for Services is then forwarded to the person or responsible party. Upon receipt of the completed application for services and other requested materials, an appointment is scheduled for the evaluation. Diagnostic and evaluation services are provided without cost to the family or person.

The interdisciplinary approach is used to assess a person's intellectual, adaptive, self-help, social, behavioral, physical, and communication abilities after a complete history is obtained.