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Elmer Y. Chang, MD
Practice accepting new patients.

Elmer Y. Chang, MD

(949) 364-5090
Primary Specialties
  • Gastroenterology
    (Board Certified)
Medical Groups & Affiliations
  • Mission Heritage Medical Group
  • Mission Hospital Affiliated Physicians
  • Additional Languages Spoken
    Mandarin Chinese, Taiwanese

Primary Office

27871 Medical Center Dr.
Suite 200
Mission Viejo, CA 92691
(949) 364-5090
(949) 364-5427

Secondary Office

St. Joseph Health Medical Group
1476 Professional Dr.
Suite 504
Recommend this Physician
4.9 out of 5 (81 Ratings | 10 Comments)


outstanding consideration and courtesy.
Excellent physician, caring human being - I consider *Dr. Elmer Chang a superior physician -
Dr. Chang is an amazing doctor. His attention to detail and problem solving methods are stellar. I am blessed and fortunate to have a doctor that knows his field, seeks the problem and finds a solution. Mission Heritage should be proud.
Great visit!
Total confidence of this doctor and have recommended him to others. My husband would continue with same doctor and was happy with him but is now on another health plan. Wish we could change that problem.
10 Total Comments Page 1 2   Next

Physician Bio

Dr. Chang is a Board Certified Gastroenterologist who specializes in the evaluation and management of disorders of the gastrointestinal tract, pancreas, bile duct, and liver.

He performs upper endoscopy and colonoscopy to screen for, diagnose, and treat a variety of gastrointestinal diseases and cancers.

He also has expertise in several advanced endoscopic techniques including endoscopic retrograde cholangiopancreatography (ERCP), a procedure that is used to manage stones, strictures, and malignant obstruction of the bile duct. He is fluent in English, Mandarin, and Taiwanese.

Dr. Chang graduated with degrees in molecular biology and economics from the Northwestern University, and received his medical degree from the Northwestern University Medical School. After finishing residency training in Internal Medicine from the Baylor College of Medicine, he completed a fellowship in gastroenterology and hepatology at the UCLA School of Medicine.

During his fellowship, Dr. Chang was recruited into the Specialty Training and Advanced Research program at UCLA, where he conducted research in gut immunity and inflammatory bowel disease. In recognition of this research, he was granted a philosophical doctorate degree from the Department of Microbiology, Immunology, and Molecular Genetics at UCLA.

He also received several awards for this work, including grants from the National Institute of Health and the Crohn's and Colitis Foundation of America.

Following his fellowship training at UCLA, Dr. Chang pursued another year of advanced endoscopic fellowship at the UCSF School of Medicine, where he developed expertise in therapeutic ERCP, endoscopic ultrasound, gastrointestinal stricture remediation, and other advanced endoscopic procedures.

Dr. Chang has published numerous abstracts and articles in the field of gut immunity, inflammatory bowel disease, and pancreaticobiliary disorders in peer-reviewed journals such as Gastroenterology, Journal of Clinical Investigation, and Journal of Immunology.

He is a member of the American Gastroenterology Association, American Society of Gastrointestinal Endoscopy, American College of Gastroenterology, and American Medical Association.


  • Medical School:
    Northwestern University School of Medicine
  • Internship:
    Baylor College of Medicine - Houston, TX
  • Residency:
    Baylor College of Medicine - Houston, TX
  • Fellowship:
    UCSF Medical Center at Parnassus - 2008
  • Fellowship:
    UCLA Medical Center - 2007
  • Board Certified in Gastroenterology


American Gastroenterology Association
American Society of Gastrointestinal Endoscopy
American College of Gastroenterology
American Medical Association

Areas of Expertise

Colon cancer screening
Heartburn or acid reflux
Peptic ulcer disease
Inflammatory bowel disease


National Institute of Health Grant Crohn's and Colitis Foundation of America Grant