Karen J. Sundby (formerly Johnson), a native of Denver, Colorado, received her undergraduate degree from the University of Arizona where she graduated Magna Cum Laude and was elected to Phi Beta Kappa honor society. She received her medical doctorate from the University of Colorado School of Medicine where she graduated in the top 5% of her class and was elected to Alpha Omega Alpha medical honor society. Dr. Sundby completed an Internal Medicine internship at the University of Colorado, then completed her Dermatology residency at the University of Colorado where she served as chief resident. She then completed a Fellowship in Mohs Micrographic Surgery and Cutaneous Oncology at the University of Pittsburgh Medical Center at Shadyside in Pittsburgh, Pennsylvania under the directorship of Drs. John A. Zitelli and David G. Brodland.

Dr. Sundby is a Board Certified Mohs Surgeon and Dermatologist. She is a member of the American Academy of Dermatology, the American College of Mohs Micrographic and Cutaneous Oncology, the American Society of Dermatologic Surgery, the American Medical Association, the Denver Medical Society, and the Colorado Dermatologic Society.

Dr. Sundby is committed to teaching and holds an appointment as Assistant Clinical Professor at the University of Colorado, Department of Dermatology and participates in teaching the dermatology resident physicians.