Claire Thuc Duyen Diep, M.D.
Internal Medicine Physician · Union City, CA
Claire Thuc Duyen Diep, M.D. is an internal medicine physician with a practice address in Union City, California, and NPI 1366508707, issued on Dec 29, 2006. Check the license (California A55900, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Claire Thuc Duyen Diep
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A55900 CA
Self-reported in NPPES; status is on the state search - Practice location
- 33509 Western Avenue, Union City, CA 94587
- Phone
- (510) 441-8081
- Enumerated
- Dec 29, 2006
- Record last updated
- Jul 17, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (510) 441-8080
- Medicaid ID
- 00A559000 CA
- Medicare enrollment
- Enrolled (PECOS I20050531000611); accepts Medicare assignment
- Medical or professional school
- Eastern Virginia Medical School, 1994
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Verify Claire Thuc Duyen Diep in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A55900Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
59% more Medicare Part D claims than the average internal medicine physician in 2024
5,044 Medicare Part D claims for 334 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 9% of claims. 29 claims were for opioids.
Most prescribed
- Atorvastatin Calcium838 claims
- Losartan Potassium486 claims
- Amlodipine Besylate482 claims
- Metformin Hcl380 claims
- Metoprolol Succinate175 claims
- Lisinopril171 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.
Claire Thuc Duyen Diep among 17,696 internal medicine physician records in California
Claire Thuc Duyen Diep, M.D. is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1994 · median 2004 among the 11,065 with a school on file
- Record last updated2007 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
46 internal medicine physician records list a practice address in Union City
They are 46 of the 1,006 NPPES records with a practice address in Union City, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Union City → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Jaishree Acharya, M.D.Union City, CA 945871053334920
- Eric Brondfield, MDUnion City, CA 945871033297882
- Nefissa Chambi, M.D.Union City, CA 945871730157157
- Vanaja Chilukuri, M.D.Union City, CA 945871861578387
- Lolita Chiong, M.D.Union City, CA 945871558387027
- Amrita Deshpande, M.D.Union City, CA 945871154409910
- Apolinar Gacote, MDUnion City, CA 945871831203652
- Yasmeen Haq, MDUnion City, CA 945871457303935
Common questions
What is Claire Thuc Duyen Diep, M.D.'s NPI number?
Claire Thuc Duyen Diep, M.D.'s National Provider Identifier (NPI) is 1366508707, issued on Dec 29, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Claire Thuc Duyen Diep, M.D. located?
The NPPES record lists a practice address at 33509 Western Avenue, Union City, CA, 94587. Phone: (510) 441-8081. Providers update this record themselves, so call before visiting.
How can I verify Claire Thuc Duyen Diep, M.D.'s license?
NPPES lists California license number A55900, 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 Claire Thuc Duyen Diep, M.D. prescribe under Medicare Part D?
In 2024, Claire Thuc Duyen Diep, M.D. had 5,044 Medicare Part D claims for 334 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
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.