From June of 1975, Dr. Stone was a Senior Clinical Psychologist in NSA's Medical Center where he performed psychological assessments pertinent to evaluation of individuals for prospective high-level security clearance.  He was also involved in 'fitness of duty' evaluations of on-board employees as well as evaluation of employees of contractor organizations.  In October of 1987, Dr. Stone became the Chief Research Psychology in the Agency's Office of Human Resouces where he remained until his retirement from federal service in January of 1997.