Robert Thomas Horvat, MD, PHD

Primary specialty

Endocrinology, Diabetes & Metabolism PhysicianTaxonomy code 207RE0101X

License

A062483 Issued in CA

Practice address

5189 Hospital Rd
Mariposa, CA 95338-9524

Phone

(209) 966-2154

Fax

(866) 206-1883

NPI assigned

Jan 10, 2006

Last updated

May 14, 2026By the provider in NPPES

Sex

Male

Sole proprietor

Yes

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

Specialties & licenses 3

Addresses

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

Internal Medicine

Education

Other, 1987

Medicare assignment

May accept Medicare assignment

Group practices

John C Fremont Healthcare DistrictGroup PAC ID 5890689533, 18 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• John C Fremont Healthcare District Hospital, Mariposa, CA, CCN 051304
• Providence Queen of the Valley Medical Center Hospital, Napa, CA, CCN 050009
• Saint Agnes Medical Center Hospital, Fresno, CA, CCN 050093
• Mercy Medical Center Hospital, Merced, CA, CCN 050444

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine, Doctor of Philosophy

State licenses

Practice roles

Locations

Interoperability endpoints

• FHIR API: https://fhir-usa.unify.chbase.com/org/fremont-d0489e1b

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

• John C Fremont Healthcare District

  dba John C Fremont Hosp Emerg Rm

  • Rural Acute Care Hospital
  • Mariposa, CA
  • NPI 1750504270
  Medicare reassignment Care Compare group NPD
• John C Fremont Healthcare District

  dba John C Fremont Healthcare District North Side

  • Family Medicine Physician
  • Coulterville, CA
  • NPI 1124248901
  NPD
• John C Fremont Healthcare District

  • Home Health Agency
  • Mariposa, CA
  • NPI 1912020488
  NPD (past)

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

• Dignity Health

  dba Mercy Medical Center Merced

  • General Acute Care Hospital
  • Merced, CA
  • NPI 1518018191
  Care Compare affiliation
• John C Fremont Healthcare District

  • Critical Access Hospital
  • Mariposa, CA
  • NPI 1184662652
  Care Compare affiliation
• Saint Agnes Medical Center

  • General Acute Care Hospital
  • Fresno, CA
  • NPI 1205845567
  Care Compare affiliation
• St. Joseph Health Northern California, LLC

  dba Providence Queen of the Valley Medical Center

  • General Acute Care Hospital
  • Napa, CA
  • NPI 1013080084
  Care Compare affiliation
• St. Joseph Health Northern California, LLC

  dba Providence Queen of the Valley Medical Center

  • General Acute Care Hospital
  • Napa, CA
  • NPI 1235218785
  Care Compare affiliation

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

{
    "created_epoch": "1136851200000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1778716800000",
    "number": "1841279668",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "2984 M ST",
            "city": "MERCED",
            "state": "CA",
            "postal_code": "953483214",
            "telephone_number": "415-265-5000"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "5189 HOSPITAL RD",
            "city": "MARIPOSA",
            "state": "CA",
            "postal_code": "953389524",
            "telephone_number": "209-966-2154",
            "fax_number": "866-206-1883"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "HORVAT",
        "first_name": "ROBERT",
        "middle_name": "THOMAS",
        "name_prefix": "Dr.",
        "credential": "MD, PHD",
        "sole_proprietor": "YES",
        "sex": "M",
        "enumeration_date": "2006-01-10",
        "last_updated": "2026-05-14",
        "certification_date": "2026-05-14",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207P00000X",
            "taxonomy_group": "",
            "desc": "Emergency Medicine",
            "state": "CA",
            "license": "A062483",
            "primary": false
        },
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "CA",
            "license": "A62483",
            "primary": false
        },
        {
            "code": "207RE0101X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Endocrinology, Diabetes & Metabolism",
            "state": "CA",
            "license": "A062483",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Pamela Jean Hawkins
• Kathaleen Maria Hefner
• Paula Henry
• Robert Hill, PARAMEDIC
• Melissa Horn
• Brandi Bae Howes-Medley, ACSW
• Debra A Hutchins, LCSW
• James Anthony Jardin
• Wendy C Jaskowiak
• Robert Jazwin, PA-C

• Endocrinology, Diabetes & Metabolism Physician in Mariposa, CA
• Providers in Mariposa, CA by specialty
• Endocrinology, Diabetes & Metabolism Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on May 14, 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.