David Jeffrey Horwitz, PAC
Medical Physician Assistant · Arcata, CA
David Jeffrey Horwitz, PAC is a medical physician assistant with a practice address in Arcata, California, and NPI 1386739845, issued on Oct 3, 2006. Check the license (California PA10646, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- David Jeffrey Horwitz
- Credential
- PAC
- Primary taxonomy
- Medical Physician Assistant 363AM0700X
- License number
- PA10646 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1150 Foster Ave, Arcata, CA 95521
- Phone
- (707) 826-8610
- Enumerated
- Oct 3, 2006
- Record last updated
- Oct 1, 2024
- Fax
- (707) 826-8623
- Medicare enrollment
- Enrolled (PECOS I20040629001446); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest medical physician assistant records → All 3,376 in California → Look up another NPI →
Also registered at 1150 Foster Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Tressa Edelman, FNPNurse Practitioner1578515961
- Julie Ohnemus, MDFamily Medicine Physician1770676306
- Katie Ray, MDFamily Medicine Physician1578875886
- Brooke Simpson, NPNurse Practitioner1184375073
Verify David Jeffrey Horwitz in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license PA10646Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.7 times the Medicare Part D claims of the average medical physician assistant in 2024
3,115 Medicare Part D claims for 170 beneficiaries, against an average of 1,148 among the 23,801 providers of this specialty who prescribed in Part D. Brand-name drugs were 17% of claims. 289 claims were for opioids.
Most prescribed
- Atorvastatin Calcium219 claims
- Hydrocodone-Acetaminophen158 claims
- Levothyroxine Sodium113 claims
- Gabapentin98 claims
- Amlodipine Besylate78 claims
- Lisinopril68 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
- Open Door Community Health CentersArcata, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
David Jeffrey Horwitz among 3,376 medical physician assistant records in California
David Jeffrey Horwitz, PAC is one of 3,376 medical physician assistant records with a practice address in California. 69% 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 2% of them.
- NPI issued2006 · 2% of these records are older, 80% newer
- In a Medicare fileYes · 69% of these records are
- In the CMS Doctors and Clinicians fileYes · 40% of these records are
- Graduated1979 · median 2012 among the 1,347 with a school on file
- Record last updated2024 · 54% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363AM0700X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Medical Physician Assistant providers in California
There are 3,376 medical physician assistant records in California.
All 3,376 in California → Every provider in Arcata → Medical Physician Assistant nationwide →
The 8 medical physician assistant records with the nearest ZIP codes
- Debra Harrison, PA-CArcata, CA 955211316945454
- Tara Moss, PACArcata, CA 955211679660187
- Anthony Rousselot, PA-CArcata, CA 955211568460608
- Katherine Schiff, PA-CArcata, CA 955211922436658
- Tracy Langhurst, PA-CMcKinleyville, CA 955191689826091
- Lorissa Lorenzo, PA-CMcKinleyville, CA 955191053970327
- Lynn Szabo, PACCrescent City, CA 955311336234806
- Laurie Thomas, PACCrescent City, CA 955311821186180
Common questions
What is David Jeffrey Horwitz, PAC's NPI number?
David Jeffrey Horwitz, PAC's National Provider Identifier (NPI) is 1386739845, issued on Oct 3, 2006. An NPI identifies a provider in billing; it is not a license.
Where is David Jeffrey Horwitz, PAC located?
The NPPES record lists a practice address at 1150 Foster Ave, Arcata, CA, 95521. Phone: (707) 826-8610. Providers update this record themselves, so call before visiting.
How can I verify David Jeffrey Horwitz, PAC's license?
NPPES lists California license number PA10646, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does David Jeffrey Horwitz, PAC prescribe under Medicare Part D?
In 2024, David Jeffrey Horwitz, PAC had 3,115 Medicare Part D claims for 170 beneficiaries; the average among medical physician assistant prescribers was 1,148. 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.