Quick answers
- Which hospitals does Theodore K. Gregorius work at?
- Medicare's official clinician data lists Theodore K. Gregorius at 2 hospitals: Hoag Memorial Hospital Presbyterian and Hoag Orthopedic Institute. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Theodore K. Gregorius see patients?
- Medicare's clinician data lists 2 practice locations, including Loma Linda, CA and Newport Beach, CA. Call before your visit to confirm the address.
- What is Theodore K. Gregorius's specialty?
- Medicare lists Orthopedic Surgery as the primary specialty.
- Does Theodore K. Gregorius accept Medicare assignment?
- Yes. Medicare's clinician data says Theodore K. Gregorius 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 Theodore K. Gregorius?
- (909) 558-2808, as listed in official Medicare / NPI Registry data.
- What is Theodore K. Gregorius's NPI number?
- 1013950450. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Theodore K. Gregorius works
Medicare's Facility Affiliation Data lists Theodore K. Gregorius at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Hoag Memorial Hospital PresbyterianNewport Beach, CA · Acute Care Hospital · CCN 050224
- Hoag Orthopedic InstituteIrvine, CA · Acute Care Hospital · CCN 050769
Practice locations
Addresses where Theodore K. Gregorius is enrolled with Medicare (CMS data updated 2026-10-02).
- 25455 Barton RdLoma Linda, CA 92354 (909) 558‑2808
- 360 San Miguel Dr, Suite 701Newport Beach, CA 92660 (714) 634‑4567
Group practices
Medicare enrollment lists Theodore K. Gregorius as a member of these groups (CMS data updated 2026-10-02).
- Faculty Physicians and Surgeons of Llusm1,315 clinicians in the group
- Orthopaedic Specialty Institute Medical Group of Orange County64 clinicians in the group
Specialties
- Orthopedic Surgeryprimary
Other orthopedic surgeons in Loma Linda
Clinicians with the same Medicare primary specialty in Loma Linda, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Loma Linda University School Of Medicine |
| Graduation year | 2000 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1013950450 |
| 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