James W. Hornstein, M.D.
Family Medicine Physician · Ventura, CA
James W. Hornstein, M.D. is a family medicine physician with a practice address in Ventura, California, and NPI 1629116587, issued on Feb 2, 2007. Check the license (California 770183168, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- James W. Hornstein
- Credential
- M.D.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- 770183168 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2793 Loma Vista RD, Ventura, CA 93003
- Phone
- (805) 643-9292
- Enumerated
- Feb 2, 2007
- Record last updated
- Mar 23, 2015 (not updated in 11 years: call before relying on the address or phone)
- Fax
- (805) 643-3626
- Medicare enrollment
- Enrolled (PECOS I20100301000227); accepts Medicare assignment
- Medical or professional school
- University Of California, Geffen School Of Medicine, 1980
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 17,133 in California → Look up another NPI →
Verify James W. Hornstein in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license 770183168Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
23% more Medicare Part D claims than the average family medicine physician in 2024
4,344 Medicare Part D claims for 360 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. 22 claims were for opioids.
Most prescribed
- Losartan Potassium452 claims
- Rosuvastatin Calcium362 claims
- Atorvastatin Calcium246 claims
- Levothyroxine Sodium203 claims
- Hydrochlorothiazide141 claims
- Metformin Hcl132 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.
No measured MIPS final score for 2023
CMS assigned the neutral MIPS final score of 75 without scoring Quality, Cost, Promoting Interoperability or Improvement Activities. It is an administrative threshold, so PlainDoctor does not compare it with measured clinicians.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
James W. Hornstein among 17,133 family medicine physician records in California
James W. Hornstein, M.D. is one of 17,133 family medicine physician records with a practice address in California. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 41% of them.
- NPI issued2007 · 41% of these records are older, 47% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 62% of these records are
- Graduated1980 · median 2005 among the 10,652 with a school on file
- Record last updated2015 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
234 family medicine physician records list a practice address in Ventura
They are 234 of the 4,435 NPPES records with a practice address in Ventura, and 17,133 family medicine physician records in California.
All 17,133 in California → Every provider in Ventura → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Charles Adams, M.D.Ventura, CA 930031811925225
- Veronica Butler, M.D.Ventura, CA 930031063472736
- Eric Chun, M.D.Ventura, CA 930031699702381
- Michelle Daucett, D.O.Ventura, CA 930031003873035
- Derrick Dcosta, M.D.Ventura, CA 930031487699005
- James Hermann, M.D.Ventura, CA 930031861442899
- Theodore Hole, M.D.Ventura, CA 930031104873611
- Andrew Kerr, M.D.Ventura, CA 930031487695078
Common questions
What is James W. Hornstein, M.D.'s NPI number?
James W. Hornstein, M.D.'s National Provider Identifier (NPI) is 1629116587, issued on Feb 2, 2007. An NPI identifies a provider in billing; it is not a license.
Where is James W. Hornstein, M.D. located?
The NPPES record lists a practice address at 2793 Loma Vista RD, Ventura, CA, 93003. Phone: (805) 643-9292. Providers update this record themselves, so call before visiting.
How can I verify James W. Hornstein, M.D.'s license?
NPPES lists California license number 770183168, 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 James W. Hornstein, M.D. prescribe under Medicare Part D?
In 2024, James W. Hornstein, M.D. had 4,344 Medicare Part D claims for 360 beneficiaries; the average among family medicine physician prescribers was 3,544. Part D covers Medicare prescriptions only.
What is James W. Hornstein, M.D.'s MIPS final score?
CMS assigned the neutral MIPS final score of 75 for 2023 without scoring any category, so it is not a measured result.
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.