Department Ranked No. 4. Hospital Ranked No. 7. City Ranked No. 2. CHCO ranked No. 1 in both the region and state of Colorado. The University of Colorado School of Medicine's Department of Pediatrics and Children's Hospital Colorado offers a three-year fellowship in Pediatric Endocrinology. The goal of the fellowship is to provide physicians who are board eligible in pediatrics with in-depth training in endocrinology which prepares them for a career in clinical or academic medicine.