Stephen Gene Ong, M.D.
Internal Medicine Physician · San Francisco, CA
Stephen Gene Ong, M.D. is an internal medicine physician with a practice address in San Francisco, California, and NPI 1780750018, issued on Nov 28, 2006. Check the license (California A93783, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Stephen Gene Ong
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A93783 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2425 Geary Blvd, San Francisco, CA 94115
- Phone
- (415) 833-2000
- Enumerated
- Nov 28, 2006
- Record last updated
- Dec 9, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20071107000402); accepts Medicare assignment
- Medical or professional school
- University Of California, San Diego School Of Medicine, 2004
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 2425 Geary Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Brian Ablang, P.T.Physical Therapist1609931054
- Arash AgharahmanianStudent in an Organized Health Care Education/Training Program1366237240
- Mia AldridgeStudent in an Organized Health Care Education/Training Program1437890761
- Catherine Grace Alejo, NPFamily Nurse Practitioner1932273521
Verify Stephen Gene Ong in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A93783Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
88% fewer Medicare Part D claims than the average internal medicine physician in 2024
376 Medicare Part D claims for 107 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 8% of claims. 14 claims were for opioids.
Most prescribed
- Atorvastatin Calcium35 claims
- Metoprolol Succinate31 claims
- Clopidogrel30 claims
- Furosemide19 claims
- Amiodarone Hcl17 claims
- Losartan Potassium16 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).
Stephen Gene Ong among 17,696 internal medicine physician records in California
Stephen Gene Ong, 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
- Graduated2004 · 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
- 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 Stephen Gene Ong, M.D.'s NPI number?
Stephen Gene Ong, M.D.'s National Provider Identifier (NPI) is 1780750018, issued on Nov 28, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Stephen Gene Ong, M.D. located?
The NPPES record lists a practice address at 2425 Geary Blvd, San Francisco, CA, 94115. Phone: (415) 833-2000. Providers update this record themselves, so call before visiting.
How can I verify Stephen Gene Ong, M.D.'s license?
NPPES lists California license number A93783, 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 Stephen Gene Ong, M.D. prescribe under Medicare Part D?
In 2024, Stephen Gene Ong, M.D. had 376 Medicare Part D claims for 107 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.