Dr. Warren Chang, MD

Dr. Chang practices at Kaiser Permanente South San Francisco Medical Center in South San Francisco, California, part of Kaiser Permanente.

Dr. Chang's NPI, 1083674550, was assigned on March 27, 2006. Dr. Chang graduated from UC Davis School of Medicine in 1998. Dr. Chang holds California license AG9500.

Dr. Chang's primary practice is Kaiser Permanente South San Francisco Medical Center, at 1200 El Camino Real, South San Francisco, CA 94080 in San Mateo County. The practice phone is (650) 742-3200.

Dr. Chang's primary practice is Kaiser Permanente South San Francisco Medical Center in South San Francisco, California, part of Kaiser Permanente. Dr. Chang is also affiliated with UCSF Helen Diller Medical Center at Parnassus Heights. The medical group on file is North East Medical Services (NEMS). Dmand AI also links Dr. Chang to 4 more hospitals, 5 dialysis centers, 3 group practices and clinics and 3 medical groups, each named with a free account.

Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Chang practices, 14 sites in all. Vendor and product names are available with a free account.

Nephrology is Dr. Chang's primary specialty in the NPI Registry, under taxonomy code 207RN0300X. Dr. Chang is board certified in internal medicine by the American Board of Internal Medicine. Dr. Chang is licensed in California.

Dmand AI lists chronic kidney disease and fluid and electrolyte imbalances among the conditions Dr. Chang treats.

CMS data shows 2,185 Medicare services from Dr. Chang across 18 procedure codes in 2024, for 448 Medicare patients. Medicare paid $209,999 for them.

CMS counts 448 Medicare patients who saw Dr. Chang in 2024. The largest group is 75 to 84, with 182 patients. 75% of them have chronic kidney disease, and 75% have high blood pressure. 43% are also on Medicaid. Their average risk score is 4.09, 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 76, with 45% women.

In 2024, Dr. Chang wrote 2,178 Medicare Part D claims for 319 patients. 78% of them were for generic drugs. CMS names the drug for 1,935 of them, across 46 drugs with 11 or more claims each, at $438,460 in total drug cost. In 2023, CMS named 1,709 claims across 40 drugs.

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

Dmand AI links 12 papers to Dr. Chang, published from 2009 to 2022. 2021 was the busiest year, with 5. The most frequent topics are Cerebral Angiography and Intracranial Aneurysm. Dr. Chang has published most often in Neuroradiol J. Dr. Chang's most frequent co-authors are Charles Li, MD, Michael P. Spearman, MD and Russell Mitesh Cerejo, MD.

CMS Open Payments shows 301 general payments to Dr. Chang from 33 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 99% of the total. AstraZeneca Pharmaceuticals LP paid the most, $1,373.

Dmand AI lists 1 award for Dr. Chang, most recently CMS Stage 1 EHR in 2013.

Dr. Chang graduated from UC Davis School of Medicine in 1998.

Dr. Chang is in network with 17 carriers, including Aetna, Blue Cross Blue Shield of Michigan and Elevance. PPO plans come from the most carriers, 10. Check the plan with the practice before a visit.