James S. Chang, M.D.
Internal Medicine Physician · San Francisco, CA
James S. Chang, M.D. is an internal medicine physician with a practice address in San Francisco, California, and NPI 1417068073, issued on Aug 31, 2006. Check the license (California A86238, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- James S. Chang
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A86238 CA
Self-reported in NPPES; status is on the state search - Practice location
- 900 Hyde St Ste 410, San Francisco, CA 94109
- Phone
- (415) 353-6817
- Enumerated
- Aug 31, 2006
- Record last updated
- Dec 13, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (415) 353-6887
- Medicaid ID
- 00A862380 CA
- Medicare enrollment
- Enrolled (PECOS I20050822000654); accepts Medicare assignment
- Medical or professional school
- Icahn School Of Medicine At Mount Sinai, 2002
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Verify James S. Chang in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A86238Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
78% fewer Medicare Part D claims than the average internal medicine physician in 2024
695 Medicare Part D claims for 156 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 23% of claims. 47 claims were for opioids.
Most prescribed
- Anastrozole222 claims
- Ibrance58 claims
- Tamoxifen Citrate34 claims
- Letrozole32 claims
- Hydroxyurea27 claims
- Lorazepam24 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 IncSanta Clara, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
James S. Chang among 17,696 internal medicine physician records in California
James S. 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 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
- Graduated2002 · 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).
1,318 internal medicine physician records list a practice address in San Francisco
They are 1,318 of the 38,143 NPPES records with a practice address in San Francisco, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in San Francisco → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Amy Bossen, M.D.San Francisco, CA 941091558371260
- Gary Chan, M.D.San Francisco, CA 941091699702324
- Guido Gores, MDSan Francisco, CA 941091528073996
- Edwin Hassid, M.D.San Francisco, CA 941091033140702
- Gayatri Khanna, M.D.San Francisco, CA 941091639191455
- Martin Liberman, MDSan Francisco, CA 941091376530006
- Deborah Lindes, M.D.San Francisco, CA 941091952323776
- Aravind Mani, MDSan Francisco, CA 941091932151941
Common questions
What is James S. Chang, M.D.'s NPI number?
James S. Chang, M.D.'s National Provider Identifier (NPI) is 1417068073, issued on Aug 31, 2006. An NPI identifies a provider in billing; it is not a license.
Where is James S. Chang, M.D. located?
The NPPES record lists a practice address at 900 Hyde St Ste 410, San Francisco, CA, 94109. Phone: (415) 353-6817. Providers update this record themselves, so call before visiting.
How can I verify James S. Chang, M.D.'s license?
NPPES lists California license number A86238, 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 James S. Chang, M.D. prescribe under Medicare Part D?
In 2024, James S. Chang, M.D. had 695 Medicare Part D claims for 156 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.