Gerald Roy Nazareno, MD
Emergency Medicine Physician · Pleasanton, CA
Gerald Roy Nazareno, MD is an emergency medicine physician with a practice address in Pleasanton, California, and NPI 1679564983, issued on Nov 4, 2005. Check the license (California A53590, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Gerald Roy Nazareno
- Credential
- MD
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- A53590 CA
Self-reported in NPPES; status is on the state search - Practice location
- 5555 W Las Positas Blvd, Pleasanton, CA 94588
- Phone
- (209) 342-2300
- Enumerated
- Nov 4, 2005
- Record last updated
- Jul 13, 2026
- Fax
- (209) 524-4240
- Medicaid ID
- 00A535900 CA
- Medicare enrollment
- Enrolled (PECOS I20040310000497); 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 5555 W Las Positas Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Dennis Alfaro, M.D.Emergency Medicine Physician1407847718
- Ashley Altman, MDDiagnostic Radiology Physician1649697947
- Joshua AshfordEmergency Registered Nurse1972458941
- Abinav Baweja, MDMedical Oncology Physician1770961575
- Brooke BettsPharmacist1962178491
- Myrna Castelazo, M.D.Diagnostic Radiology Physician1407290513
Verify Gerald Roy Nazareno in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A53590Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
18% more Medicare Part D claims than the average emergency medicine physician in 2024
266 Medicare Part D claims for 183 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D. 33 claims were for opioids.
Most prescribed
- Cefadroxil38 claims
- Tramadol Hcl32 claims
- Methylprednisolone21 claims
- Azithromycin16 claims
- Doxycycline Hyclate15 claims
- Albuterol Sulfate Hfa12 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 100 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Pleasanton Emergency Medical GroupLivermore, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gerald Roy Nazareno among 7,751 emergency medicine physician records in California
Gerald Roy Nazareno, 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 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 96% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated1987 · median 2011 among the 4,560 with a school on file
- Record last updated2026 · 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).
27 emergency medicine physician records list a practice address in Pleasanton
They are 27 of the 2,213 NPPES records with a practice address in Pleasanton, and 7,751 emergency medicine physician records in California.
All 7,751 in California → Every provider in Pleasanton → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Dennis Alfaro, M.D.Pleasanton, CA 945881407847718
- Paul Chasin, MDPleasanton, CA 945881649261959
- Michael Costello, MDPleasanton, CA 945881477544781
- Colleen Johnson, MDPleasanton, CA 945881720079049
- Edward Kan, MDPleasanton, CA 945881104804426
- Robert MandibergPleasanton, CA 945881336130640
- Cynthia Penn-Duecker, MDPleasanton, CA 945881033100359
- Scott Seidman, MDPleasanton, CA 945881184605230
Common questions
What is Gerald Roy Nazareno, MD's NPI number?
Gerald Roy Nazareno, MD's National Provider Identifier (NPI) is 1679564983, issued on Nov 4, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Gerald Roy Nazareno, MD located?
The NPPES record lists a practice address at 5555 W Las Positas Blvd, Pleasanton, CA, 94588. Phone: (209) 342-2300. Providers update this record themselves, so call before visiting.
How can I verify Gerald Roy Nazareno, MD's license?
NPPES lists California license number A53590, 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 Gerald Roy Nazareno, MD prescribe under Medicare Part D?
In 2024, Gerald Roy Nazareno, MD had 266 Medicare Part D claims for 183 beneficiaries; the average among emergency medicine physician prescribers was 226. Part D covers Medicare prescriptions only.
What is Gerald Roy Nazareno, MD's MIPS final score?
The 2023 MIPS final score is 100 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.