Hans D. Gruenn, M.D.
Family Medicine Physician · Ojai, CA
Hans D. Gruenn, M.D. is a family medicine physician with a practice address in Ojai, California, and NPI 1649398371, issued on Mar 27, 2007. Check the license (California A51484, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Hans D. Gruenn
- Credential
- M.D.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- A51484 CA
Self-reported in NPPES; status is on the state search - Practice location
- 350 W. Ojai Ave, Ojai, CA 93023
- Phone
- (058) 633-9121
- Enumerated
- Mar 27, 2007
- Record last updated
- Nov 17, 2020 (not updated in 6 years: call before relying on the address or phone)
- Fax
- (805) 633-9151
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 17,133 in California → Look up another NPI →
Verify Hans D. Gruenn in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A51484Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
80% fewer Medicare Part D claims than the average family medicine physician in 2024
712 Medicare Part D claims for 91 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 7% of claims.
Most prescribed
- Levothyroxine Sodium66 claims
- Rosuvastatin Calcium45 claims
- Trazodone Hcl39 claims
- Valacyclovir29 claims
- Amlodipine Besylate27 claims
- Dotti24 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.
Hans D. Gruenn among 17,133 family medicine physician records in California
Hans D. Gruenn, 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 fileNo · 62% of these records are
- Record last updated2020 · 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).
13 family medicine physician records list a practice address in Ojai
They are 13 of the 271 NPPES records with a practice address in Ojai, and 17,133 family medicine physician records in California.
All 17,133 in California → Every provider in Ojai → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Sterling Adams, DOOjai, CA 930231629539887
- Preston Arndt, M.D.Ojai, CA 930231346303336
- Daniel Demirchyan, MDOjai, CA 930231740639046
- Mary Dial, M.D.Ojai, CA 930231962468553
- Kristyna Fong, D.O.Ojai, CA 930231801294657
- Carl Gross, M.D.Ojai, CA 930231497711451
- James Halverson, M.D.Ojai, CA 930231720044787
- Maria Halvorson, DOOjai, CA 930231164446704
Common questions
What is Hans D. Gruenn, M.D.'s NPI number?
Hans D. Gruenn, M.D.'s National Provider Identifier (NPI) is 1649398371, issued on Mar 27, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Hans D. Gruenn, M.D. located?
The NPPES record lists a practice address at 350 W. Ojai Ave, Ojai, CA, 93023. Phone: (058) 633-9121. Providers update this record themselves, so call before visiting.
How can I verify Hans D. Gruenn, M.D.'s license?
NPPES lists California license number A51484, 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 Hans D. Gruenn, M.D. prescribe under Medicare Part D?
In 2024, Hans D. Gruenn, M.D. had 712 Medicare Part D claims for 91 beneficiaries; the average among family medicine physician prescribers was 3,544. 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.