Dr. Tammy T. Chang, MD, PhD

Dr. Chang practices at UCSF Helen Diller Medical Center at Parnassus Heights in San Francisco, California, part of University of California Health.

Dr. Chang's NPI, 1972787174, was assigned on December 24, 2007. Dr. Chang graduated from Harvard Medical School in 2003. Dr. Chang holds California license A90279.

Dr. Chang's primary practice is UCSF Helen Diller Medical Center at Parnassus Heights, at 505 Parnassus Ave, Box 0296, San Francisco, CA 94143 in San Francisco County. The practice phone is (415) 353-2733.

Dr. Chang's primary practice is UCSF Helen Diller Medical Center at Parnassus Heights in San Francisco, California, part of University of California Health. The medical group on file is UCSF Pediatrics. Dmand AI also links Dr. Chang to 4 more group practices and clinics and 4 medical groups, each named with a free account.

Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Chang practices, 5 sites in all. Vendor and product names are available with a free account.

Surgery is Dr. Chang's primary specialty in the NPI Registry, under taxonomy code 208600000X. Dr. Chang is board certified in surgery by the American Board of Surgery. Dr. Chang is licensed in California.

Dmand AI lists appendectomy, gallbladder removal and gastrointestinal obstruction among the conditions Dr. Chang treats.

CMS data shows 84 Medicare services from Dr. Chang across 4 procedure codes in 2024, for 32 Medicare patients. Medicare paid $7,612 for them. Every service was in a facility, such as a hospital, rather than an office.

CMS counts 32 Medicare patients who saw Dr. Chang in 2024. The largest group is 75 to 84, with 16 patients. 75% of them have high cholesterol, and 72% have high blood pressure. Their average risk score is 2.01, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.

Across all payers, Dmand AI patient panel data puts Dr. Chang's median patient age at 66, with 62% women.

CMS publishes a Merit-based Incentive Payment System (MIPS) score of 98 out of 100 for Dr. Chang for performance year 2024, reported as part of a group. Dr. Chang accepts Medicare assignment, so Medicare's approved amount is taken as full payment.

Colonoscopy: 1 to 10 procedures (CMS shows small counts as a range)

Hernia repair - groin (open): 1 to 10 procedures (CMS shows small counts as a range)

Removal of tissue: 1 to 10 procedures (CMS shows small counts as a range)

Dmand AI links 25 papers to Dr. Chang, published from 2008 to 2025. 2023 was the busiest year, with 4. The most frequent topics are Liver, Electroporation and Hepatocytes. Dr. Chang has published most often in J Surg Res. Dr. Chang's most frequent co-authors are Tasce Riika Simon Bongiovanni, MD, Li Che, DO and Won-Tak Choi, MD, PhD.

CMS Open Payments shows 1 general payment to Dr. Chang from 1 drug or device company in 2020. Gifts make up the largest share, 100% of the total. Ormco Corporation paid the most, $13.

Dmand AI lists 1 award for Dr. Chang.

Dr. Chang graduated from Harvard Medical School in 2003. Dr. Chang is a member of ACS.

Dr. Chang is in network with 8 carriers, including Aetna, Blue Cross Blue Shield of Michigan and United Healthcare. Medicare plans come from the most carriers, 7. Check the plan with the practice before a visit.