Robert Morris O'Hollaren, M.D.

Primary specialty

Adult Reconstructive Orthopaedic Surgery PhysicianTaxonomy code 207XS0114X

License

G39131 Issued in CA

Practice address

1191 Church St
Ventura, CA 93001-2148

Phone

(805) 320-6761

NPI assigned

Apr 21, 2006

Last updated

Jul 13, 2026By the provider in NPPES

Sex

Male

Sole proprietor

No

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

Specialties & licenses 1

Addresses

Other identifiers 1

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

Orthopedic Surgery

Education

University of Southern California Keck School of Medicine, 1977

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Ventura Orthopedics Medical Group IncGroup PAC ID 2062312911, 79 clinicians

Practice addresses (Care Compare)

Merit-based Incentive Payment System (MIPS)

Final score

73.77 of 100Reported as group

Quality

31.85

Promoting interoperability

98

Improvement activities

40

Cost

82.39

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: robert.ohollaren@vo1.eclinicaldirectplus.com

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

• Ventura Orthopedics Medical Group, Inc.

  dba Ventura Orthopedics

  • Specialist
  • Ventura, CA
  • NPI 1871547315
  Medicare reassignment Care Compare group
• Ventura Orthopedics Medical Group, Inc.

  dba Ventura Orthopedics

  • Specialist
  • Thousand Oaks, CA
  • NPI 1104389931

  Adult Reconstructive Orthopaedic Surgery

  NPD
• Community Memorial Health System

  dba Community Memorial Hospital - Ventura

  • General Acute Care Hospital
  • Ventura, CA
  • NPI 1215903018
  NPD (past)
• Dignity Health

  dba St. John's Regional Medical Center

  • General Acute Care Hospital
  • Oxnard, CA
  • NPI 1073665360
  NPD (past)

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

{
    "created_epoch": "1145577600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1783900800000",
    "number": "1801852710",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1191 CHURCH ST",
            "city": "VENTURA",
            "state": "CA",
            "postal_code": "930012148",
            "telephone_number": "805-320-6761"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1191 CHURCH ST",
            "city": "VENTURA",
            "state": "CA",
            "postal_code": "930012148",
            "telephone_number": "805-320-6761"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "O'HOLLAREN",
        "first_name": "ROBERT",
        "middle_name": "MORRIS",
        "name_prefix": "Dr.",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-04-21",
        "last_updated": "2026-07-13",
        "certification_date": "2026-07-13",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207XS0114X",
            "taxonomy_group": "",
            "desc": "Orthopaedic Surgery, Adult Reconstructive Orthopaedic Surgery",
            "state": "CA",
            "license": "G39131",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "STATE LICENSE",
            "identifier": "G39131",
            "state": "CA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Maureen Ann O'Brien, PHARMD
• Carlos Eduardo O'Bryan-Becerra, M.D.
• Dennis O'Connell, LCSW
• Terrence O'Connor, M.A., MFT
• Ronald O'Halloran, M.D.
• Kimberly O'Neill
• Kerry Elizabeth O'Reilly, PSYD, LMFT
• Samantha O'Rourke
• Frances O'Sullivan
• Bridget Oberle

• Adult Reconstructive Orthopaedic Surgery Physician in Ventura, CA
• Providers in Ventura, CA by specialty
• Adult Reconstructive Orthopaedic Surgery Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jul 13, 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.