John O'Brien Clarke, M.D.
Gastroenterology Physician · Palo Alto, CA
John O'Brien Clarke, M.D. is a gastroenterology physician with a practice address in Palo Alto, California, and NPI 1467539643, issued on Nov 1, 2006. Check the license (California C143081, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- John O'Brien Clarke
- Credential
- M.D.
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License numbers
- C143081 CA
D58832 MD
Self-reported in NPPES; status is on the state search - Practice location
- 300 Pasteur Dr, Palo Alto, CA 94304
- Phone
- (650) 723-4000
- Enumerated
- Nov 1, 2006
- Record last updated
- Apr 28, 2024
- Medicaid ID
- 411750600 MD
- Medicare enrollment
- Enrolled (PECOS I20160819000945); accepts Medicare assignment
- Medical or professional school
- University Of Missouri, Columbia School Of Medicine, 1999
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 2,140 in California → Look up another NPI →
Also registered at 300 Pasteur Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Teddy Akiki, MDPsychiatry Physician1942867718
- Amy Alexander, M.D.Psychiatry Physician1740435486
- Monica Allen, PSYDClinical Psychologist1952787749
Verify John O'Brien Clarke in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license C143081Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
11% more Medicare Part D claims than the average gastroenterology physician in 2024
901 Medicare Part D claims for 244 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D.
Most prescribed
- Pantoprazole Sodium87 claims
- Dexlansoprazole Dr76 claims
- Omeprazole65 claims
- Motegrity54 claims
- Esomeprazole Magnesium53 claims
- Famotidine53 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The practice group's MIPS final score for 2023 (Medicare payment program): 76.5 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $18.73
1 payment: food and beverage; the largest payer was Regeneron Healthcare Solutions, Inc. The 13,350 providers of this specialty with any payment received $5,015.95 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
One hospital affiliation
- Stanford Health CareStanford, CA · Acute Care Hospitals5 of 5 stars
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through); hospitals matched to CMS Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.
John O'Brien Clarke among 2,140 gastroenterology physician records in California
John O'Brien Clarke, M.D. is one of 2,140 gastroenterology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 7% of them.
- NPI issued2006 · 7% of these records are older, 48% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated1999 · median 2002 among the 1,538 with a school on file
- Record last updated2024 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0100X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Gastroenterology Physician providers in California
There are 2,140 gastroenterology physician records in California.
All 2,140 in California → Every provider in Palo Alto → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Matthew Chang, M.D.Palo Alto, CA 943041598949521
- Ramsey Cheung, MDPalo Alto, CA 943041750394532
- Tami Daugherty, M.D.Palo Alto, CA 943041194742064
- Samer Eldika, M.D.Palo Alto, CA 943041346267093
- Nielsen Fernandez-Becker, M.D., PH.D.Palo Alto, CA 943041972678639
- Harry Greenberg, MDPalo Alto, CA 943041689731200
- Peter Gregory, M.DPalo Alto, CA 943041891889903
- Joanne Imperial, MDPalo Alto, CA 943041225101884
Common questions
What is John O'Brien Clarke, M.D.'s NPI number?
John O'Brien Clarke, M.D.'s National Provider Identifier (NPI) is 1467539643, issued on Nov 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is John O'Brien Clarke, M.D. located?
The NPPES record lists a practice address at 300 Pasteur Dr, Palo Alto, CA, 94304. Phone: (650) 723-4000. Providers update this record themselves, so call before visiting.
How can I verify John O'Brien Clarke, M.D.'s license?
NPPES lists California license number C143081, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does John O'Brien Clarke, M.D. prescribe under Medicare Part D?
In 2024, John O'Brien Clarke, M.D. had 901 Medicare Part D claims for 244 beneficiaries; the average among gastroenterology physician prescribers was 811. Part D covers Medicare prescriptions only.
What is John O'Brien Clarke, M.D.'s MIPS final score?
The 2023 MIPS final score is 76.5 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.