Warren Joseph A. San Diego, MD
Internal Medicine Physician · Fairfield, CA
Warren Joseph A. San Diego, MD is an internal medicine physician with a practice address in Fairfield, California, and NPI 1083036743, issued on Jan 15, 2014. Check the license (California A130099, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Warren Joseph A. San Diego
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A130099 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1200 B Gale Wilson Blvd, Fairfield, CA 94533
- Phone
- (707) 646-5080
- Enumerated
- Jan 15, 2014
- Record last updated
- Jul 22, 2019 (not updated in 7 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20140822001676); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 1200 B Gale Wilson Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Yusuf Ahmad, MDAnesthesiology Physician1104020262
- Tashira AlexanderRegistered Dietitian1902732480
- Nail Amro, M.D.Internal Medicine Physician1861413551
- Allan Au, M.D.Hospitalist Physician1427495563
- Erin Berntsen, ACNPAcute Care Nurse Practitioner1205640489
- Neeta BhasinCritical Care Pharmacist1457984882
Verify Warren Joseph A. San Diego in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A130099Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
86% fewer Medicare Part D claims than the average internal medicine physician in 2024
443 Medicare Part D claims for 147 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 9% of claims. 23 claims were for opioids.
Most prescribed
- Pantoprazole Sodium38 claims
- Cefpodoxime Proxetil27 claims
- Atorvastatin Calcium21 claims
- Doxycycline Monohydrate16 claims
- Metoprolol Tartrate15 claims
- Amoxicillin-Clavulanate Potass14 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
- Northbay Physicians Surgery Center, LLCFairfield, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Warren Joseph A. San Diego among 17,696 internal medicine physician records in California
Warren Joseph A. San Diego, 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 2014, is newer than 74% of them.
- NPI issued2014 · 74% of these records are older, 24% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2011 · median 2004 among the 11,065 with a school on file
- Record last updated2019 · 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).
54 internal medicine physician records list a practice address in Fairfield
They are 54 of the 3,595 NPPES records with a practice address in Fairfield, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Fairfield → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Sumera Ahmed, MDFairfield, CA 945331134180219
- Nail Amro, M.D.Fairfield, CA 945331861413551
- Shulan Ding, MDFairfield, CA 945331811075351
- Daniel Green, MDFairfield, CA 945331386731602
- Svetlana Gutierrez, M.D.Fairfield, CA 945331619990637
- Jane Hewitt, MDFairfield, CA 945331629156526
- James Horodyski, M.D.Fairfield, CA 945331184710063
- Matthew Johnson, MDFairfield, CA 945331659487395
Common questions
What is Warren Joseph A. San Diego, MD's NPI number?
Warren Joseph A. San Diego, MD's National Provider Identifier (NPI) is 1083036743, issued on Jan 15, 2014. An NPI identifies a provider in billing; it is not a license.
Where is Warren Joseph A. San Diego, MD located?
The NPPES record lists a practice address at 1200 B Gale Wilson Blvd, Fairfield, CA, 94533. Phone: (707) 646-5080. Providers update this record themselves, so call before visiting.
How can I verify Warren Joseph A. San Diego, MD's license?
NPPES lists California license number A130099, 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 Warren Joseph A. San Diego, MD prescribe under Medicare Part D?
In 2024, Warren Joseph A. San Diego, MD had 443 Medicare Part D claims for 147 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.