Dr. John O'Brien Clarke III, MD

Dr. Clarke practices at Stanford Hospital at 300 Pasteur Drive in Stanford, California, part of Stanford University.

Dr. Clarke's NPI, 1467539643, was assigned on November 1, 2006. Dr. Clarke graduated from Vagelos College of Physicians and Surgeons in 1999. Dr. Clarke holds California license C143081.

Dr. Clarke's primary practice is Stanford Hospital at 300 Pasteur Drive, at 300 Pasteur Drive, Stanford, CA 94305 in Santa Clara County. The practice phone is (650) 723-4000.

Dr. Clarke's primary practice is Stanford Hospital at 300 Pasteur Drive in Stanford, California, part of Stanford University. The medical group on file is Stanford Health Care. Dmand AI also links Dr. Clarke to 1 more hospital and 1 group practice or clinic, each named with a free account. Dr. Clarke's employer is on file too: a hospital.

Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Clarke practices, 3 sites in all. Vendor and product names are available with a free account.

Gastroenterology is Dr. Clarke's primary specialty in the NPI Registry, under taxonomy code 207RG0100X. Dr. Clarke is board certified in gastroenterology by the American Board of Internal Medicine. Dmand AI has Dr. Clarke's licenses on file in 2 states: California and Maryland.

Dmand AI lists acid reflux, acute stomach ulcer, colonoscopy, fatty liver, gastroenteritis, gastrointestinal bleeding, hemorrhoids and intestinal or bowel obstruction among the conditions Dr. Clarke treats.

CMS data shows 1,377 Medicare services from Dr. Clarke across 25 procedure codes in 2024, for 593 Medicare patients. Medicare paid $105,207 for them.

CMS counts 593 Medicare patients who saw Dr. Clarke in 2024. The largest group is 65 to 74, with 265 patients. 72% of them have high cholesterol, and 65% have high blood pressure. 23% are also on Medicaid. Their average risk score is 1.80, 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. Clarke's median patient age at 54, with 60% women.

In 2024, Dr. Clarke wrote 901 Medicare Part D claims for 244 patients. 75% of them were for generic drugs. CMS names the drug for 612 of them, across 17 drugs with 11 or more claims each, at $224,731 in total drug cost. In 2023, CMS named 560 claims across 16 drugs.

CMS publishes a Merit-based Incentive Payment System (MIPS) score of 89 out of 100 for Dr. Clarke for performance year 2024, reported as part of a group. Dr. Clarke accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS lists Dr. Clarke as offering telehealth. CMS counts 317 procedures of upper gastrointestinal (gi) endoscopy for acid reflux by Dr. Clarke, more than 96% of the clinicians it reports for that procedure.

Dmand AI links 142 papers to Dr. Clarke, published from 2007 to 2025. 2020 was the busiest year, with 15. The most frequent topics are Gastroesophageal Reflux, Manometry and Esophageal Achalasia. Dr. Clarke has published most often in Neurogastroenterol Motil. Dr. Clarke's most frequent co-authors are George Triadafilopoulos, MD, Thomas Antonios Zikos, MD and Jonathan Michael Buscaglia, MD.

CMS Open Payments shows 34 general payments to Dr. Clarke from 15 drug and device companies from 2016 to 2025. Consulting fees make up the largest share, 60% of the total. Sanofi and Genzyme US Companies paid the most, $15,561. It also lists 8 research payments totaling $10,497 from 2017 to 2025.

Dr. Clarke graduated from Vagelos College of Physicians and Surgeons in 1999.

Dr. Clarke is in network with 11 carriers, including Aetna, Excellus BlueCross BlueShield and Blue Cross Blue Shield of Michigan. Medicare plans come from the most carriers, 8. Check the plan with the practice before a visit.