Quick answers
- Which hospitals does James J. Ong work at?
- Medicare's official clinician data lists James J. Ong at 4 hospitals: Los Robles Hospital & Medical Center, Northridge Hospital Medical Center, Providence Cedars Sinai Tarzana Medical Center and St Johns Regional Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does James J. Ong see patients?
- Medicare's clinician data lists 1 practice location in Tarzana, CA. Call before your visit to confirm the address.
- What is James J. Ong's specialty?
- Medicare lists Cardiac Electrophysiology as the primary specialty.
- Does James J. Ong accept Medicare assignment?
- Yes. Medicare's clinician data says James J. Ong 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.
- Does James J. Ong offer telehealth?
- Medicare's clinician data says James J. Ong offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for James J. Ong?
- (818) 342-5377, as listed in official Medicare / NPI Registry data.
- What is James J. Ong's NPI number?
- 1912955980. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where James J. Ong works
Medicare's Facility Affiliation Data lists James J. Ong 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
- Northridge Hospital Medical CenterNorthridge, CA · Acute Care Hospital · CCN 050116
- Providence Cedars Sinai Tarzana Medical CenterTarzana, CA · Acute Care Hospital · CCN 050761
- St Johns Regional Medical CenterOxnard, CA · Acute Care Hospital · CCN 050082
Practice locations
Addresses where James J. Ong is enrolled with Medicare (CMS data updated 2026-10-02).
- 18372 Clark St, Suite 218Tarzana, CA 91356 (818) 342‑5377
Specialties
- Cardiac Electrophysiologyprimary
Find other Cardiac Electrophysiology doctors in California →
Other cardiac electrophysiologists in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, San Diego School Of Medicine |
| Graduation year | 1989 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1912955980 |
| 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