Gwendolen Chang, M.D.
Internal Medicine Physician · San Leandro, CA
Gwendolen Chang, M.D. is an internal medicine physician with a practice address in San Leandro, California, and NPI 1386807402, issued on Jul 9, 2008. Check the license (California A106132, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Gwendolen Chang
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A106132 CA
Self-reported in NPPES; status is on the state search - Practice location
- 13851 E 14TH St Ste 206, San Leandro, CA 94578
- Phone
- (510) 351-9373
- Enumerated
- Jul 9, 2008
- Record last updated
- Dec 4, 2013 (not updated in 13 years: call before relying on the address or phone)
- Fax
- (510) 351-0616
- Medicare enrollment
- Enrolled (PECOS I20110106000994); accepts Medicare assignment
- Medical or professional school
- Stanford University School Of Medicine, 2007
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 13851 E 14TH St Ste 206
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Lydia Andemariam, NPFamily Nurse Practitioner1114736667
- Gee Tsou, PA-CMedical Physician Assistant1316147580
- Anne Yu, MDNephrology Physician1114283314
Verify Gwendolen Chang in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A106132Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
33% fewer Medicare Part D claims than the average internal medicine physician in 2024
2,140 Medicare Part D claims for 243 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.
Most prescribed
- Amlodipine Besylate260 claims
- Farxiga176 claims
- Furosemide118 claims
- Bumetanide110 claims
- Allopurinol105 claims
- Losartan Potassium101 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.
Industry payments in 2024: $1,283.92
53 payments; by number, the most common kind was food and beverage; the largest payer was Novartis Pharmaceuticals Corporation. The 50,334 providers of this specialty with any payment received $1,303.06 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.
Bills Medicare through one group practice
- West Coast KidneySan Leandro, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gwendolen Chang among 17,696 internal medicine physician records in California
Gwendolen Chang, 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
- Graduated2007 · median 2004 among the 11,065 with a school on file
- Record last updated2013 · 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).
62 internal medicine physician records list a practice address in San Leandro
They are 62 of the 4,976 NPPES records with a practice address in San Leandro, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in San Leandro → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Deepak Dhawan, MDSan Leandro, CA 945781184727182
- Nehal GhevariyaSan Leandro, CA 945781518203728
- Dennis Ha, MDSan Leandro, CA 945781922460617
- Sejal Jhatakia, M.D.San Leandro, CA 945781871577312
- Rubinder KaurSan Leandro, CA 945781295049740
- Padmavathi Madathanapalli, MDSan Leandro, CA 945781336253152
- Namrata PatyalSan Leandro, CA 945781063607919
- Kruthika Proddatoori, M.DSan Leandro, CA 945781679955694
Common questions
What is Gwendolen Chang, M.D.'s NPI number?
Gwendolen Chang, M.D.'s National Provider Identifier (NPI) is 1386807402, issued on Jul 9, 2008. An NPI identifies a provider in billing; it is not a license.
Where is Gwendolen Chang, M.D. located?
The NPPES record lists a practice address at 13851 E 14TH St Ste 206, San Leandro, CA, 94578. Phone: (510) 351-9373. Providers update this record themselves, so call before visiting.
How can I verify Gwendolen Chang, M.D.'s license?
NPPES lists California license number A106132, 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 Gwendolen Chang, M.D. prescribe under Medicare Part D?
In 2024, Gwendolen Chang, M.D. had 2,140 Medicare Part D claims for 243 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.