Dr. Walder received his medical degree from the University of Illinois at the Medical Center in Chicago, Illinois. Upon completion of residencies at Baptist Memorial Hospital in Memphis, Tennessee, and William Beaumont Army Medical Center in El Paso, Texas, he completed his fellowship in cardiovascular disease at Fitzsimmons Army Medical Center in Denver, Colorado. Dr. Walder began practicing cardiology at Tripler Army Medical Center in Honolulu, Hawaii. He later joined a private practice in Albuquerque, New Mexico, where he practiced until 2002 when he relocated to Rapid City to join the Heart Doctors.

Dr. Walder is Board Certified in Internal Medicine, Cardiovascular Disease, Interventional Cardiology, and Nuclear Cardiology.