Meet Dr. Oppenheimer


Mark J. Oppenheimer, M.D. has been practicing endocrinology in Sioux Falls since 1989. He opened Oppenheimer Endocrinology in 2005. Since then, the practice has grown to serve patients across the Midwest.

Dr. Oppenheimer is also a clinical associate professor at the Sanford School of Medicine of the University of South Dakota.


  • Princeton University, B.A. with Honors, Chemistry
  • University of Minnesota, Doctor of Medicine
  • Medical Residency and Internship, State University of New York at Buffalo
  • Senior Research Fellow, Division of Metabolism, Endocrinology and Nutrition,¬†Department of Medicine, University of Washington in Seattle


  • Diplomat, National Board of Medical Examiners
  • American Board of Internal Medicine
  • American Board of Internal Medicine, Endocrinology, Diabetes and Metabolism
  • Fellow, American College of Physicians
  • Fellow, American Association of Clinical Endocrinologists¬†


In his personal time, you might find Dr. Oppenheimer in the middle of a competitive Scrabble game, working on embroidery or exercising. His interest in art and photography are apparent throughout his beautiful, spacious clinic.


Dr. Oppenheimer is originally from New York. He is married with two adult children.