David Eugene Whitehead JR.

A psychologist, certified/licensed at the independent practice level in his/her state, who is duly trained and experienced in the delivery of direct, preventative, assessment, and therapeutic intervention services to individuals whose growth, adjustment, or functioning is actually impaired or is demonstrably at high risk of impairment (1974).

A person who provides case management services and assists an individual in gaining access to needed medical, social, educational, and/or other services. The person has the ability to provide an assessment and review of completed plan of care on a periodic basis. This person is also able to take collaborative action to coordinate the services with other providers and monitor the enrollee's progress toward the cost-effective achievement of objectives specified in the plan of care. Credentials may vary from an experience in the fields of psychology, social work, rehabilitation, nursing or a closely related human service field, to a related Assoc of Arts Degree or to nursing credentials. Some states may require certification in case management.

Source: NUCC, CMS