Gerald Roy Nazareno, MD

Primary specialty

Emergency Medicine PhysicianTaxonomy code 207P00000X

License

A53590 Issued in CA

Practice address

5555 W Las Positas Blvd
Pleasanton, CA 94588-4000

Phone

(209) 342-2300

Fax

(209) 524-4240

NPI assigned

Nov 4, 2005

Sex

Male

Sole proprietor

No

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 1

Addresses

Other identifiers 2

Medicare fee-for-service enrollment

Enrolled in CA

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 1

Specialty

Emergency Medicine

Education

Other, 1987

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Pleasanton Emergency Medical GroupGroup PAC ID 0143118927, 38 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Stanford Health Care Tri-Valley Hospital, Pleasanton, CA, CCN 050283

Merit-based Incentive Payment System (MIPS)

Final score

82.7 of 100Reported as group

Quality

57.11

Promoting interoperability

100

Improvement activities

40

Cost

73.85

Procedures performed for Medicare patients

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

Practice roles

Locations

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

• Pleasanton Emergency Medical Group

  • Emergency Medicine Physician
  • Pleasanton, CA
  • NPI 1285625509
  Medicare reassignment Care Compare group NPD

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

• Stanford Health Care Tri-Valley

  • General Acute Care Hospital
  • Pleasanton, CA
  • NPI 1144389941
  Care Compare affiliation

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1131062400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1783900800000",
    "number": "1679564983",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "4301 NORTHSTAR WAY",
            "city": "MODESTO",
            "state": "CA",
            "postal_code": "953569262",
            "telephone_number": "209-342-2300",
            "fax_number": "209-524-4240"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "5555 W LAS POSITAS BLVD",
            "city": "PLEASANTON",
            "state": "CA",
            "postal_code": "945884000",
            "telephone_number": "209-342-2300",
            "fax_number": "209-524-4240"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "NAZARENO",
        "first_name": "GERALD",
        "middle_name": "ROY",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2005-11-04",
        "last_updated": "2026-07-13",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207P00000X",
            "taxonomy_group": "",
            "desc": "Emergency Medicine",
            "state": "CA",
            "license": "A53590",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "00A535900",
            "state": "CA"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "BLUE SHIELD",
            "identifier": "00A535900",
            "state": "CA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• National Vision, Inc.
• National Vision, Inc.
• Clarissa Navarro, BA
• Navin Mallavaram, M.D., Inc.
• Nisha Perampalli Nayak, DMD
• Sierra Lashawn Nazel
• Lauren Ashley Nelson, M.D.
• Ruku Nepal
• Steven Nerad, D.M.D.
• Nest Health, Inc

• Emergency Medicine Physician in Pleasanton, CA
• Providers in Pleasanton, CA by specialty
• Emergency Medicine Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jul 13, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.