Stanley Andrew Tan, MD
Endocrinology, Diabetes & Metabolism Physician · Castro Valley, CA
Stanley Andrew Tan, MD is an endocrinology, diabetes & metabolism physician with a practice address in Castro Valley, California, and NPI 1396747721, issued on Aug 15, 2005. Check the license (California G23082, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Stanley Andrew Tan
- Credential
- MD
- Primary taxonomy
- Endocrinology, Diabetes & Metabolism Physician 207RE0101X
- License numbers
- G23082 CA
ME94328 FL
2003-00713 NC
Self-reported in NPPES; status is on the state search - Practice location
- 20642 John Dr, Castro Valley, CA 94546
- Phone
- (510) 785-5000
- Enumerated
- Aug 15, 2005
- Record last updated
- Oct 8, 2025
- Medicaid IDs
- 89133MT NC
PENDING FL - Medicare enrollment
- Enrolled (PECOS I20051028000449); accepts Medicare assignment
- Medical or professional school
- Loma Linda University School Of Medicine, 1971
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest endocrinology, diabetes & metabolism physician records → All 1,131 in California → Look up another NPI →
Also registered at 20642 John Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Kalaokalani Chandler, M.D.Obstetrics & Gynecology Physician1164459947
- Shiven Chaudhry, MDInternal Medicine Physician1528594801
- Corina Clark, P.A.Physician Assistant1720480049
- Ashley Etchison, MDDiagnostic Radiology Physician1962907840
Verify Stanley Andrew Tan in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G23082Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
91% fewer Medicare Part D claims than the average endocrinology, diabetes & metabolism physician in 2024
231 Medicare Part D claims for 109 beneficiaries, against an average of 2,630 among the 8,223 providers of this specialty who prescribed in Part D.
Most prescribed
- Levothyroxine Sodium41 claims
- Glipizide15 claims
- Jardiance15 claims
- Glimepiride13 claims
- Prolia13 claims
- Trulicity11 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.
Stanley Andrew Tan among 1,131 endocrinology, diabetes & metabolism physician records in California
Stanley Andrew Tan, MD is one of 1,131 endocrinology, diabetes & metabolism physician records with a practice address in California. 84% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 95% newer
- In a Medicare fileYes · 84% of these records are
- In the CMS Doctors and Clinicians fileYes · 69% of these records are
- Graduated1971 · median 2003 among the 779 with a school on file
- Record last updated2025 · 57% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RE0101X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Endocrinology, Diabetes & Metabolism Physician providers in California
There are 1,131 endocrinology, diabetes & metabolism physician records in California.
All 1,131 in California → Every provider in Castro Valley → Endocrinology, Diabetes & Metabolism Physician nationwide →
The 8 endocrinology, diabetes & metabolism physician records with the nearest ZIP codes
- Amer Budayr, MDCastro Valley, CA 945461700958451
- Jennifer CaseyCastro Valley, CA 945461750524575
- Nalurporn Chokrungvaranon, M.D.Castro Valley, CA 945461922209436
- Samuel Fantaye, MDCastro Valley, CA 945461336677186
- Farnoosh FarrokhiCastro Valley, CA 945461467618454
- Susana Harbutt, M.D.Castro Valley, CA 945461588007678
- Marcia Peck, MDCastro Valley, CA 945461376569475
- Frank Hsu, M.D.Hayward, CA 945411295800365
Common questions
What is Stanley Andrew Tan, MD's NPI number?
Stanley Andrew Tan, MD's National Provider Identifier (NPI) is 1396747721, issued on Aug 15, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Stanley Andrew Tan, MD located?
The NPPES record lists a practice address at 20642 John Dr, Castro Valley, CA, 94546. Phone: (510) 785-5000. Providers update this record themselves, so call before visiting.
How can I verify Stanley Andrew Tan, MD's license?
NPPES lists California license number G23082, 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 Stanley Andrew Tan, MD prescribe under Medicare Part D?
In 2024, Stanley Andrew Tan, MD had 231 Medicare Part D claims for 109 beneficiaries; the average among endocrinology, diabetes & metabolism physician prescribers was 2,630. 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.