Quick answers
- Which hospitals does Ronald J. Rivera work at?
- Medicare's official clinician data lists Ronald J. Rivera at 1 hospital: UCI Health-Orange. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Ronald J. Rivera see patients?
- Medicare's clinician data lists 1 practice location in Orange, CA. Call before your visit to confirm the address.
- What is Ronald J. Rivera's specialty?
- Medicare lists Emergency Medicine as the primary specialty.
- Does Ronald J. Rivera accept Medicare assignment?
- Yes. Medicare's clinician data says Ronald J. Rivera 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 Ronald J. Rivera?
- (714) 456-7004, as listed in official Medicare / NPI Registry data.
- What is Ronald J. Rivera's NPI number?
- 1558716233. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Ronald J. Rivera works
Medicare's Facility Affiliation Data lists Ronald J. Rivera at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- UCI Health-OrangeOrange, CA · Acute Care Hospital · CCN 050348
Practice locations
Addresses where Ronald J. Rivera is enrolled with Medicare (CMS data updated 2026-10-02).
- 101 the City Dr SOrange, CA 92868 (714) 456‑7004
Group practices
Medicare enrollment lists Ronald J. Rivera as a member of this group (CMS data updated 2026-10-02).
- Regents of the University of129 clinicians in the group
Specialties
- Emergency Medicineprimary
Other emergency medicine doctors in Orange
Clinicians with the same Medicare primary specialty in Orange, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, Geffen School Of Medicine |
| Graduation year | 2016 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1558716233 |
| 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