An accomplished physician with a broad history in emergency and general family medicine, Dr. Koock Jung ultimately narrowed his focus to psychiatry and the specific treatment of post-traumatic stress disorder and sexual trauma. From his private offices in Queensbury, New York, he concentrated on these fields from 1980 to 2015, serving a diverse patient base through direct clinical oversight and social worker supervision. Dr. Koock Jung has served as a diplomate of the American Psychiatric Association, a fellow of the American College of Forensic Examiners, a founding fellow of the Pacific Rim College of Psychiatrists, and has earned multiple designations as a top regional and national physician.

In 2011, Dr. Koock Jung reached out to a larger population with the release of his Hudson Press textbook on sexual trauma entitled Sexual Trauma: A Challenge, Not Insanity. He has also contributed articles to multiple professional journals and subchapters to the 1980 medical textbook Tardive Dyskensia.