Dr. Kieffer joined the faculty in 2018. He completed his pediatrics residency at St. Louis Children's Hospital and earned his medical degree at Washington University Medical School in St. Louis, Missouri. He earned his bachelor’s degree in chemistry at Yale University in New Haven, Connecticut. Board certified by the American Board of Pediatrics, he is a member of the American Academy of Pediatrics. He lives in Springfield with his wife and son where he is an active cyclist, runner, and swimmer.