Daniel O'Brien

Primary specialty

Cardiovascular Disease PhysicianTaxonomy code 207RC0000X

License

A165839 Issued in CA

Practice address

501 Deep Valley Dr Ste 100
Rolling Hills Estates, CA 90274-7606

Phone

(310) 303-3953

Fax

(310) 303-7903

NPI assigned

Mar 20, 2018

Sex

Male

Sole proprietor

Yes

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 1

Addresses

Medicare fee-for-service enrollment

Enrolled in CA

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 1

Specialty

Cardiovascular Disease (Cardiology)Also: Hospitalist, Internal Medicine

Education

University of Southern California Keck School of Medicine, 2018

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Telehealth

Offers telehealth services

Group practices

The Regents of the University of CaliforniaGroup PAC ID 1355248584, 1,426 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Torrance Memorial Medical Center Hospital, Torrance, CA, CCN 050351
• Providence Little Company of Mary Med Ctr Torrance Hospital, Torrance, CA, CCN 050353
• Ronald Reagan UCLA Medical Center Hospital, Los Angeles, CA, CCN 050262

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

• The Regents of the University of California

  • Internal Medicine Physician
  • Los Angeles, CA
  • NPI 1235107566
  Medicare reassignment Care Compare group

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

• Providence Health System Southern California

  • General Acute Care Hospital
  • Torrance, CA
  • NPI 1902844988
  Care Compare affiliation
• Regents Univ of Calif Los Angeles

  • General Acute Care Hospital
  • Los Angeles, CA
  • NPI 1902803315
  Care Compare affiliation
• Torrance Memorial Medical Center

  • General Acute Care Hospital
  • Torrance, CA
  • NPI 1467459776
  Care Compare affiliation

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1521504000000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1774396800000",
    "number": "1023512431",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "5767 W CENTURY BLVD STE 400",
            "city": "LOS ANGELES",
            "state": "CA",
            "postal_code": "900455631"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "501 DEEP VALLEY DR STE 100",
            "city": "ROLLING HILLS ESTATES",
            "state": "CA",
            "postal_code": "902747606",
            "telephone_number": "310-303-3953",
            "fax_number": "310-303-7903"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "757 Westwood Plz",
            "address_purpose": "LOCATION",
            "city": "Los Angeles",
            "state": "CA",
            "postal_code": "900958358",
            "country_code": "US",
            "telephone_number": "310-825-9111",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "address_1": "200 Ucla Medical Plz Ste 420",
            "address_purpose": "LOCATION",
            "city": "Los Angeles",
            "state": "CA",
            "postal_code": "900958358",
            "country_code": "US",
            "telephone_number": "310-206-6232",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "O'BRIEN",
        "first_name": "DANIEL",
        "sole_proprietor": "YES",
        "sex": "M",
        "enumeration_date": "2018-03-20",
        "last_updated": "2026-03-25",
        "certification_date": "2026-03-25",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207RC0000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Cardiovascular Disease",
            "state": "CA",
            "license": "A165839",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

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• Pacific Coast Mental Health

• Cardiovascular Disease Physician in Rolling Hills Estates, CA
• Providers in Rolling Hills Estates, CA by specialty
• Cardiovascular Disease Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Mar 25, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.