He has been in private practice since 2002, prior to which he provided psychological services as a master’s level psychologist in the juvenile justice system and community agencies from 1994 until earning his Ph.D. in 2000. Dr. Hammel and his wife, Lisa Hammel, M.Ed., are the co-founders of the Neurobehavioral Institute of Austin, a multidisciplinary mental health practice that also provides educational consulting for young children.