Board certified in thoracic surgery, Dr. Howell graduated with a degree in biology from the University of Texas at Arlington before earning his medical degree from the University of Texas Medical Branch in Galveston, Texas. He completed general surgery and thoracic surgery training at the University of Oklahoma Health Sciences Center after which he served three years as assistant professor in thoracic surgery. Additionally, during residency, he completed a research fellowship at the National Heart and Lung Institute in London, UK.

He has served in the past as a flight surgeon in the U.S. Air Force Reserve, earning the Air Force Meritorious Achievement Medal. He is a member of the American College of Surgeons, Society of Thoracic Surgeons, Oklahoma State Medical Association and Oklahoma County Medical Society.