Quick answers
- Which hospitals does James D. Obrien work at?
- Medicare's official clinician data lists James D. Obrien at 2 hospitals: Hoag Memorial Hospital Presbyterian and UCI Health-Orange. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does James D. Obrien see patients?
- Medicare's clinician data lists 1 practice location in Irvine, CA. Call before your visit to confirm the address.
- What is James D. Obrien's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does James D. Obrien accept Medicare assignment?
- Medicare's clinician data says James D. Obrien 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 James D. Obrien?
- (949) 272-3800, as listed in official Medicare / NPI Registry data.
- What is James D. Obrien's NPI number?
- 1922188168. 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 D. Obrien works
Medicare's Facility Affiliation Data lists James D. Obrien 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
- UCI Health-OrangeOrange, CA · Acute Care Hospital · CCN 050348
Practice locations
Addresses where James D. Obrien is enrolled with Medicare (CMS data updated 2026-10-02).
- 4870 Barranca Pkwy, Suite 250Irvine, CA 92604 (949) 272‑3800
Group practices
Medicare enrollment lists James D. Obrien as a member of this group (CMS data updated 2026-10-02).
- Spectrum Internal Medicine Associates, Inc. a Professional Corporation2 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Irvine
Clinicians with the same Medicare primary specialty in Irvine, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | New York Medical College |
| Graduation year | 1992 |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1922188168 |
| 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