Dr. Kessinger has been in private practice since 1964. Early in his professional career, he developed a special interest in total health care, emphasizing treatment and prevention of degenerative disease. He continues to operate a multi-discipline, alternative-care clinic in Rolla, Missouri.

He has authored numerous articles published in professional journals on the effectiveness of natural health care. He has lectured throughout the United States, in addition to providing post-graduate seminars for Texas Chiropractic College, Logan College of Chiropractic, National University of Health Sciences and Northwestern Health Sciences University.

He is past-president of the American Chiropractic Association's Council on Diagnosis and Internal Disorders (ACA-CDID), past-president of the Missouri State Chiropractic Association, a member of ACA Council on Diagnostic Imaging, Council of Nutrition, Council on Diagnosis and Internal Disorders. He also holds membership in each of the following: American Preventive Medical Association and American Naturopathic Medical Association. He is the Missouri delegate for the ACA.

He serves as Editor-in-Chief for the Original Internist and regularly produces informative editorial and scientific articles. He hosts a weekly radio program titled A Healthy Concept.