Sergio Jose Marquez, MD
Emergency Medicine Physician · Loma Linda, CA
Sergio Jose Marquez, MD is an emergency medicine physician with a practice address in Loma Linda, California, and NPI 1851967178, issued on May 27, 2021. Check the license (California A198101, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Sergio Jose Marquez
- Credential
- MD
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- A198101 CA
Self-reported in NPPES; status is on the state search - Practice location
- 11234 Anderson Street, Gme Office Westerly Suite C, Loma Linda, CA 92354
- Phone
- (909) 558-4085
- Enumerated
- May 27, 2021
- Record last updated
- Oct 3, 2025
- Medicare enrollment
- Enrolled (PECOS I20240925000956); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 7,751 in California → Look up another NPI →
Also registered at 11234 Anderson Street, Gme Office Westerly Suite C
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Armando Camacho-Santos, MDInternal Medicine Physician1700453933
- Jeannie Choi, MDStudent in an Organized Health Care Education/Training Program1619672474
- Mohamed El-FarraStudent in an Organized Health Care Education/Training Program1245923119
- Eun Hye Joo, MDStudent in an Organized Health Care Education/Training Program1194577874
Verify Sergio Jose Marquez in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A198101Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
85% fewer Medicare Part D claims than the average emergency medicine physician in 2024
34 Medicare Part D claims for 26 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D.
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 2 group practices
- EM Alliance California ApcWildomar, CA
- Singh MD A Professional MedicalBarstow, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Sergio Jose Marquez among 7,751 emergency medicine physician records in California
Sergio Jose Marquez, MD is one of 7,751 emergency medicine physician records with a practice address in California. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2021, is newer than 92% of them.
- NPI issued2021 · 92% of these records are older, 5% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated2021 · median 2011 among the 4,560 with a school on file
- Record last updated2025 · 59% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207P00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
168 emergency medicine physician records list a practice address in Loma Linda
They are 168 of the 4,863 NPPES records with a practice address in Loma Linda, and 7,751 emergency medicine physician records in California.
All 7,751 in California → Every provider in Loma Linda → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Robert Bassler, M.D.Loma Linda, CA 923541184675902
- Lance Brown, M.D.Loma Linda, CA 923541376562793
- Deepak Chandwani, M.D.Loma Linda, CA 923541144264177
- Tony Chow, M.D.Loma Linda, CA 923541154340578
- Lynda Daniel-Underwood, M.D.Loma Linda, CA 923541063447241
- Jeff Grange, M.D.Loma Linda, CA 923541801815238
- Steven Green, M.D.Loma Linda, CA 923541619996048
- Gregory Guldner, M.D.Loma Linda, CA 923541932125523
Common questions
What is Sergio Jose Marquez, MD's NPI number?
Sergio Jose Marquez, MD's National Provider Identifier (NPI) is 1851967178, issued on May 27, 2021. An NPI identifies a provider in billing; it is not a license.
Where is Sergio Jose Marquez, MD located?
The NPPES record lists a practice address at 11234 Anderson Street, Gme Office Westerly Suite C, Loma Linda, CA, 92354. Phone: (909) 558-4085. Providers update this record themselves, so call before visiting.
How can I verify Sergio Jose Marquez, MD's license?
NPPES lists California license number A198101, 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 Sergio Jose Marquez, MD prescribe under Medicare Part D?
In 2024, Sergio Jose Marquez, MD had 34 Medicare Part D claims for 26 beneficiaries; the average among emergency medicine physician prescribers was 226. 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.