Quick answers
- Which hospitals does Daniel P. O'Brien work at?
- Medicare's official clinician data lists Daniel P. O'Brien at 3 hospitals: Providence Little Company of Mary Med Ctr Torrance, Ronald Reagan UCLA Medical Center and Torrance Memorial Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Daniel P. O'Brien see patients?
- Medicare's clinician data lists 3 practice locations, including Santa Monica, CA, Torrance, CA and Rolling Hills Estates, CA. Call before your visit to confirm the address.
- What is Daniel P. O'Brien's specialty?
- Medicare lists Cardiovascular Disease (Cardiology) as the primary specialty, and also Hospitalist and Internal Medicine.
- Does Daniel P. O'Brien accept Medicare assignment?
- Yes. Medicare's clinician data says Daniel P. O'Brien 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 Daniel P. O'Brien offer telehealth?
- Medicare's clinician data says Daniel P. O'Brien offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Daniel P. O'Brien?
- (310) 458-2381, as listed in official Medicare / NPI Registry data.
- What is Daniel P. O'Brien's NPI number?
- 1023512431. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Daniel P. O'Brien works
Medicare's Facility Affiliation Data lists Daniel P. O'Brien at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Providence Little Company of Mary Med Ctr TorranceTorrance, CA · Acute Care Hospital · CCN 050353
- Ronald Reagan UCLA Medical CenterLos Angeles, CA · Acute Care Hospital · CCN 050262
- Torrance Memorial Medical CenterTorrance, CA · Acute Care Hospital · CCN 050351
Practice locations
Addresses where Daniel P. O'Brien is enrolled with Medicare (CMS data updated 2026-10-02).
- 2020 Santa Monica Blvd, Suite 210Santa Monica, CA 90404 (310) 458‑2381
- 3500 Lomita Blvd, Suite 300Torrance, CA 90505 (310) 257‑0028
- 501 Deep Valley Dr, Suite 100Rolling Hills Estates, CA 90274 (310) 303‑3953
Group practices
Medicare enrollment lists Daniel P. O'Brien as a member of this group (CMS data updated 2026-10-02).
- The Regents of the University of California1,462 clinicians in the group
Specialties
Find other Cardiovascular Disease (Cardiology) doctors in California →
Other cardiologists in Santa Monica
Clinicians with the same Medicare primary specialty in Santa Monica, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Southern California Keck School Of Medicine |
| Graduation year | 2018 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1023512431 |
| 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