Ann M. Chen, MD
Gastroenterology Physician · Stanford, CA
Ann M. Chen, MD is a gastroenterology physician with a practice address in Stanford, California, and NPI 1003840307, issued on Jul 10, 2006. Check the license (California A76890, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Ann M. Chen
- Credential
- MD
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- A76890 CA
Self-reported in NPPES; status is on the state search - Practice location
- 300 Pasteur Dr, Stanford, CA 94305
- Phone
- (650) 725-3376
- Enumerated
- Jul 10, 2006
- Record last updated
- Jan 10, 2009 (not updated in 17 years: call before relying on the address or phone)
- Fax
- (650) 723-8305
- Medicare enrollment
- Enrolled (PECOS I20041215000417); accepts Medicare assignment
- Medical or professional school
- Albert Einstein College Of Medicine Of Yeshiva University, 2000
- 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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Verify Ann M. Chen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A76890Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
83% fewer Medicare Part D claims than the average gastroenterology physician in 2024
138 Medicare Part D claims for 35 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 17% of claims.
Most prescribed
- Omeprazole47 claims
- Entecavir17 claims
- Famotidine17 claims
- Linzess12 claims
- Peg-3350 And Electrolytes12 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): 80.6 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).
Bills Medicare through one group practice
- County OF Santa ClaraSan Jose, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Ann M. Chen among 2,140 gastroenterology physician records in California
Ann M. Chen, MD 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
- Graduated2000 · median 2002 among the 1,538 with a school on file
- Record last updated2009 · 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).
70 gastroenterology physician records list a practice address in Stanford
They are 70 of the 5,606 NPPES records with a practice address in Stanford, and 2,140 gastroenterology physician records in California.
All 2,140 in California → Every provider in Stanford → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Aijaz Ahmed, MDStanford, CA 943051447351747
- Ashish Atreja, MDStanford, CA 943051831152883
- Shai Friedland, M.D.Stanford, CA 943051316034655
- Jeffrey Glenn, M.D., PH.D.Stanford, CA 943051366523946
- Joo Hwang, MDStanford, CA 943051194815043
- Paul Kwo, M.D.Stanford, CA 943051578527008
- Uri Ladabaum, MDStanford, CA 943051245288059
- David Limsui, M.D.Stanford, CA 943051568449650
Common questions
What is Ann M. Chen, MD's NPI number?
Ann M. Chen, MD's National Provider Identifier (NPI) is 1003840307, issued on Jul 10, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Ann M. Chen, MD located?
The NPPES record lists a practice address at 300 Pasteur Dr, Stanford, CA, 94305. Phone: (650) 725-3376. Providers update this record themselves, so call before visiting.
How can I verify Ann M. Chen, MD's license?
NPPES lists California license number A76890, 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 Ann M. Chen, MD prescribe under Medicare Part D?
In 2024, Ann M. Chen, MD had 138 Medicare Part D claims for 35 beneficiaries; the average among gastroenterology physician prescribers was 811. Part D covers Medicare prescriptions only.
What is Ann M. Chen, MD's MIPS final score?
The 2023 MIPS final score is 80.6 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.