NPPES file of Aug 9, 2026

Robert Morris O'Hollaren, M.D.

Adult Reconstructive Orthopaedic Surgery Physician · Ventura, CA

Robert Morris O'Hollaren, M.D. is an adult reconstructive orthopaedic surgery physician with a practice address in Ventura, California, and NPI 1801852710, issued on Apr 21, 2006. Check the license (California G39131, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1801852710
Name
Robert Morris O'Hollaren
Credential
M.D.
Primary taxonomy
Adult Reconstructive Orthopaedic Surgery Physician 207XS0114X
License number
G39131 CA
Self-reported in NPPES; status is on the state search
Practice location
1191 Church St, Ventura, CA 93001
Phone
(805) 320-6761
Enumerated
Apr 21, 2006
Record last updated
Jul 13, 2026
Medicare enrollment
Enrolled (PECOS I20100201000046); accepts Medicare assignment
Medical or professional school
University Of Southern California Keck School Of Medicine, 1977
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Verify Robert Morris O'Hollaren in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G39131
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

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60% fewer Medicare Part D claims than the average adult reconstructive orthopaedic surgery physician in 2024

233 Medicare Part D claims for 74 beneficiaries, against an average of 579 among the 1,112 providers of this specialty who prescribed in Part D. 22 claims were for opioids.

  1. Robert O'Hollaren233
  2. Specialty average579

Most prescribed

  1. Meloxicam98 claims
  2. Celecoxib27 claims
  3. Methylprednisolone20 claims
  4. Tramadol Hcl14 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

Bills Medicare through one group practice

  1. Ventura Orthopedics Medical Group IncVentura, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Robert Morris O'Hollaren among 147 adult reconstructive orthopaedic surgery physician records in California

Robert Morris O'Hollaren, M.D. is one of 147 adult reconstructive orthopaedic surgery physician records with a practice address in California. 88% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 5% of them.

  • NPI issued2006 · 5% of these records are older, 68% newer
  • In a Medicare fileYes · 88% of these records are
  • In the CMS Doctors and Clinicians fileYes · 76% of these records are
  • Graduated1977 · median 2009 among the 112 with a school on file
  • Record last updated2026 · 47% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207XS0114X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Adult Reconstructive Orthopaedic Surgery Physician providers in California

There are 147 adult reconstructive orthopaedic surgery physician records in California.

The 8 adult reconstructive orthopaedic surgery physician records with the nearest ZIP codes

  1. Thomas Horn, M.D.Ventura, CA 930031194781005
  2. Mary Ragsdale, M.D.Ventura, CA 930031295977957
  3. Mario Vargas-Vila, MD, PHDVentura, CA 930031134501307
  4. Craig Zeman, M.D.Oxnard, CA 930301710943618
  5. Gary Bradley, MDSanta Barbara, CA 931011386756724
  6. Ryan Digiovanni, MDOrange, CA 928681720440951
  7. Bang Hoang, MDOrange, CA 928681568542629
  8. Peter Hsiue, M.D.Orange, CA 928681679935944

Common questions

What is Robert Morris O'Hollaren, M.D.'s NPI number?

Robert Morris O'Hollaren, M.D.'s National Provider Identifier (NPI) is 1801852710, issued on Apr 21, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Robert Morris O'Hollaren, M.D. located?

The NPPES record lists a practice address at 1191 Church St, Ventura, CA, 93001. Phone: (805) 320-6761. Providers update this record themselves, so call before visiting.

How can I verify Robert Morris O'Hollaren, M.D.'s license?

NPPES lists California license number G39131, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does Robert Morris O'Hollaren, M.D. prescribe under Medicare Part D?

In 2024, Robert Morris O'Hollaren, M.D. had 233 Medicare Part D claims for 74 beneficiaries; the average among adult reconstructive orthopaedic surgery physician prescribers was 579. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.