Quick answers
- Which hospitals does Gregory P. Fontana work at?
- Medicare's official clinician data lists Gregory P. Fontana at 1 hospital: Los Robles Hospital & Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Gregory P. Fontana see patients?
- Medicare's clinician data lists 1 practice location in Thousand Oaks, CA. Call before your visit to confirm the address.
- What is Gregory P. Fontana's specialty?
- Medicare lists Thoracic Surgery as the primary specialty, and also Cardiac Surgery.
- Does Gregory P. Fontana accept Medicare assignment?
- Yes. Medicare's clinician data says Gregory P. Fontana accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Gregory P. Fontana?
- (805) 852-9100, as listed in official Medicare / NPI Registry data.
- What is Gregory P. Fontana's NPI number?
- 1508840570. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Gregory P. Fontana works
Medicare's Facility Affiliation Data lists Gregory P. Fontana at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Los Robles Hospital & Medical CenterThousand Oaks, CA · Acute Care Hospital · CCN 050549
Practice locations
Addresses where Gregory P. Fontana is enrolled with Medicare (CMS data updated 2026-10-02).
- 215 W Janss RdThousand Oaks, CA 91360 (805) 852‑9100
Group practices
Medicare enrollment lists Gregory P. Fontana as a member of this group (CMS data updated 2026-10-02).
- Golden State Providers, a Medical Corporation23 clinicians in the group
Specialties
- Thoracic Surgeryprimary
- Cardiac Surgeryalso
Other thoracic surgeons in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, Geffen School Of Medicine |
| Graduation year | 1984 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1508840570 |
| 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