Quick answers
- Which hospitals does Robert T. Horvat work at?
- Medicare's official clinician data lists Robert T. Horvat at 4 hospitals: John C Fremont Healthcare District, Mercy Medical Center, Providence Queen of the Valley Medical Center and Saint Agnes Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Robert T. Horvat see patients?
- Medicare's clinician data lists 3 practice locations, including Napa, CA and Mariposa, CA. Call before your visit to confirm the address.
- What is Robert T. Horvat's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Robert T. Horvat accept Medicare assignment?
- Medicare's clinician data says Robert T. Horvat may accept Medicare assignment (as of 2026-10-02). Ask the office whether they accept it for your visit.
- What is the phone number for Robert T. Horvat?
- (415) 265-5000, as listed in official Medicare / NPI Registry data.
- What is Robert T. Horvat's NPI number?
- 1841279668. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Robert T. Horvat works
Medicare's Facility Affiliation Data lists Robert T. Horvat at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- John C Fremont Healthcare DistrictMariposa, CA · Critical Access Hospital · CCN 051304
- Mercy Medical CenterMerced, CA · Acute Care Hospital · CCN 050444
- Providence Queen of the Valley Medical CenterNapa, CA · Acute Care Hospital · CCN 050009
- Saint Agnes Medical CenterFresno, CA · Acute Care Hospital · CCN 050093
Practice locations
Addresses where Robert T. Horvat is enrolled with Medicare (CMS data updated 2026-10-02).
- 2100 Napa Valley HwyNapa, CA 94558 (415) 265‑5000
- 5186 Hospital RdMariposa, CA 95338 (209) 966‑3631
- 5189 Hospital RdMariposa, CA 95338 (209) 966‑3631
Group practices
Medicare enrollment lists Robert T. Horvat as a member of this group (CMS data updated 2026-10-02).
- John C Fremont Healthcare District18 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Napa
Clinicians with the same Medicare primary specialty in Napa, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1987 |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1841279668 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians