Ryan C. Chang, MD
Critical Care Medicine (Internal Medicine) Physician · San Francisco, CA
Ryan C. Chang, MD is a critical care medicine (internal medicine) physician with a practice address in San Francisco, California, and NPI 1831277417, issued on Nov 1, 2006. Check the license (California A63692, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Ryan C. Chang
- Credential
- MD
- Primary taxonomy
- Critical Care Medicine (Internal Medicine) Physician 207RC0200X
- License number
- A63692 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2200 Ofarrell St, San Francisco, CA 94115
- Phone
- (415) 833-2000
- Enumerated
- Nov 1, 2006
- Record last updated
- Dec 13, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicaid ID
- 00A636920 CA
- Medicare enrollment
- Enrolled (PECOS I20110131000008); accepts Medicare assignment
- Medical or professional school
- George Washington University School Of Medicine, 1996
- Entity
- Type 1 · individual
8 nearest critical care medicine (internal medicine) physician records → All 723 in California → Look up another NPI →
Also registered at 2200 Ofarrell St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Mitchell Adachi, MDAnatomic Pathology Physician1720166366
- Lesley Aiken, MDInternal Medicine Physician1629156120
- Jonathan Alexander, MDHospitalist Physician1811075450
- Gabull Alhadhrami, NPAcute Care Nurse Practitioner1427124098
- Bryan Andrews, MDAnesthesiology Physician1609954239
Verify Ryan C. Chang in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A63692Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
73% fewer Medicare Part D claims than the average critical care medicine (internal medicine) physician in 2024
190 Medicare Part D claims for 57 beneficiaries, against an average of 696 among the 2,873 providers of this specialty who prescribed in Part D. Brand-name drugs were 47% of claims.
Most prescribed
- Albuterol Sulfate Hfa30 claims
- Stiolto Respimat23 claims
- Alvesco22 claims
- Azithromycin15 claims
- Fluticasone Propionate15 claims
- Prednisone15 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 IncSan Francisco, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Ryan C. Chang among 723 critical care medicine (internal medicine) physician records in California
Ryan C. Chang, MD is one of 723 critical care medicine (internal medicine) physician records with a practice address in California. 87% 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 6% of them.
- NPI issued2006 · 6% of these records are older, 60% newer
- In a Medicare fileYes · 87% of these records are
- In the CMS Doctors and Clinicians fileYes · 77% of these records are
- Graduated1996 · median 2005 among the 559 with a school on file
- Record last updated2021 · 50% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RC0200X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Critical Care Medicine (Internal Medicine) Physician providers in California
There are 723 critical care medicine (internal medicine) physician records in California.
All 723 in California → Every provider in San Francisco → Critical Care Medicine (Internal Medicine) Physician nationwide →
The 8 critical care medicine (internal medicine) physician records with the nearest ZIP codes
- Mehrdad Arjomandi, MDSan Francisco, CA 941151912951153
- Ivan Cheng, MDSan Francisco, CA 941151639253438
- Michael Coppolino, MDSan Francisco, CA 941151700964350
- Scott Ferguson, MDSan Francisco, CA 941151770661373
- Sheryl Goldyn, MD, MPHSan Francisco, CA 941151770783250
- Noreen Henig, MDSan Francisco, CA 941151881778686
- James Hershon, MDSan Francisco, CA 941151508940305
- George Horng, MDSan Francisco, CA 941151306924972
Common questions
What is Ryan C. Chang, MD's NPI number?
Ryan C. Chang, MD's National Provider Identifier (NPI) is 1831277417, issued on Nov 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Ryan C. Chang, MD located?
The NPPES record lists a practice address at 2200 Ofarrell St, San Francisco, CA, 94115. Phone: (415) 833-2000. Providers update this record themselves, so call before visiting.
How can I verify Ryan C. Chang, MD's license?
NPPES lists California license number A63692, 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 Ryan C. Chang, MD prescribe under Medicare Part D?
In 2024, Ryan C. Chang, MD had 190 Medicare Part D claims for 57 beneficiaries; the average among critical care medicine (internal medicine) physician prescribers was 696. 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.