Stephen Chen, M.D.
Internal Medicine Physician · Oakland, CA
Stephen Chen, M.D. is an internal medicine physician with a practice address in Oakland, California, and NPI 1265601553, issued on Feb 21, 2008. Check the license (California A102205, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Stephen Chen
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A102205 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1800 Harrison St, Oakland, CA 94612
- Phone
- (510) 625-6262
- Enumerated
- Feb 21, 2008
- Record last updated
- Dec 20, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20081029000231); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 1800 Harrison St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Fahmida Akhter AlamFamily Medicine Physician1902334451
- Julie Do, PHARMDPharmacist1194096800
- Kristen Frimpong-Boateng, M.D.Family Medicine Physician1720442601
- Andrew Fung, PHARMDPharmacist1477992493
Verify Stephen Chen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A102205Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
70% fewer Medicare Part D claims than the average internal medicine physician in 2024
966 Medicare Part D claims for 190 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 15% of claims. 458 claims were for opioids.
Most prescribed
- Hydrocodone-Acetaminophen119 claims
- Oxycontin99 claims
- Dexamethasone76 claims
- Oxycodone-Acetaminophen63 claims
- Trazodone Hcl62 claims
- Oxycodone Hcl55 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.
Bills Medicare through one group practice
- Permanente Medical Group IncModesto, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Stephen Chen among 17,696 internal medicine physician records in California
Stephen Chen, 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 2008, is newer than 56% of them.
- NPI issued2008 · 56% of these records are older, 40% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2005 · median 2004 among the 11,065 with a school on file
- Record last updated2021 · 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).
432 internal medicine physician records list a practice address in Oakland
They are 432 of the 18,558 NPPES records with a practice address in Oakland, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Oakland → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Ameena Ahmed, MDOakland, CA 946121700962230
- Andrew Avins, M.D.Oakland, CA 946121346354792
- Ronald Chun, M.D.Oakland, CA 946121730162264
- Tri Do, MDOakland, CA 946121053402651
- Susan Fernyak, MDOakland, CA 946121679688014
- Alan Go, MDOakland, CA 946121184700619
- Kathleen Grannan, MDOakland, CA 946121538245063
- Coleman GrossOakland, CA 946121538193388
Common questions
What is Stephen Chen, M.D.'s NPI number?
Stephen Chen, M.D.'s National Provider Identifier (NPI) is 1265601553, issued on Feb 21, 2008. An NPI identifies a provider in billing; it is not a license.
Where is Stephen Chen, M.D. located?
The NPPES record lists a practice address at 1800 Harrison St, Oakland, CA, 94612. Phone: (510) 625-6262. Providers update this record themselves, so call before visiting.
How can I verify Stephen Chen, M.D.'s license?
NPPES lists California license number A102205, 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 Stephen Chen, M.D. prescribe under Medicare Part D?
In 2024, Stephen Chen, M.D. had 966 Medicare Part D claims for 190 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.