After earning his medical degree, Jenkins continued his education at the OU Health Sciences Center with his internship and residency in internal medicine. From 1993 to 2013, he practiced at Warren Clinic in Stillwater, a division of the Saint Francis Health System. Since 2013, he has practiced at the Stillwater Medical Physicians Clinic, a division of Stillwater Medical Center.
Jenkins has served in several leadership roles at Stillwater Medical Center, including Chief of Medicine and Chief of Staff. He has been active with the Oklahoma State Medical Association, currently serving as co-chair of the OSMA Rural Section. He previously served as president of OSMA and chairman of its board of trustees. He currently serves as president of the Payne-Pawnee-Noble County Medical Society.
He has received several honors, including the Ed Calhoon, M.D. Leadership in Medicine Award from the Oklahoma State Medical Association, in recognition of his distinguished leadership and service to organized medicine. He was also awarded the Tim K. Smalley Leadership Award by the medical staff of Stillwater Medical Center for his outstanding leadership, professionalism, clinical expertise, friendship and mentorship.