Mark Jung Chen, MD
Internal Medicine Physician · San Francisco, CA
Mark Jung Chen, MD is an internal medicine physician with a practice address in San Francisco, California, and NPI 1891989190, issued on Aug 29, 2007. Check the license (California A99948, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Mark Jung Chen
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A99948 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2238 Geary Blvd, San Francisco, CA 94115
- Phone
- (415) 833-2200
- Enumerated
- Aug 29, 2007
- Record last updated
- May 14, 2010 (not updated in 16 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 2238 Geary Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Mark Jung Chen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A99948Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
99% fewer Medicare Part D claims than the average internal medicine physician in 2024
39 Medicare Part D claims for 32 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 54% of claims.
Most prescribed
- Adacel Tdap13 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.
Mark Jung Chen among 17,696 internal medicine physician records in California
Mark Jung Chen, MD 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 2007, is newer than 44% of them.
- NPI issued2007 · 44% of these records are older, 44% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileNo · 63% of these records are
- Record last updated2010 · 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
- Gary Arsham, M.D.San Francisco, CA 941151487646758
- Richard Caplin, M.D.San Francisco, CA 941151568443455
- C Cooney, M.D.San Francisco, CA 941151255332094
- Sarita Dubey, MDSan Francisco, CA 941151316905466
- Meredith Heller, M.D.San Francisco, CA 941151073562096
- Alan Leung, MDSan Francisco, CA 941151245222330
- Susan Nguyen, MDSan Francisco, CA 941151164470696
- Daniel Null, MDSan Francisco, CA 941151689638744
Common questions
What is Mark Jung Chen, MD's NPI number?
Mark Jung Chen, MD's National Provider Identifier (NPI) is 1891989190, issued on Aug 29, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Mark Jung Chen, MD located?
The NPPES record lists a practice address at 2238 Geary Blvd, San Francisco, CA, 94115. Phone: (415) 833-2200. Providers update this record themselves, so call before visiting.
How can I verify Mark Jung Chen, MD's license?
NPPES lists California license number A99948, 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 Mark Jung Chen, MD prescribe under Medicare Part D?
In 2024, Mark Jung Chen, MD had 39 Medicare Part D claims for 32 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.