NPPES file of Aug 9, 2026

William Dale Hasson, M.D.

Family Medicine Physician · Napa, CA

William Dale Hasson, M.D. is a family medicine physician with a practice address in Napa, California, and NPI 1235662677, issued on Apr 4, 2017. Check the license (California A169243, 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
1235662677
Name
William Dale Hasson
Credential
M.D.
Primary taxonomy
Family Medicine Physician 207Q00000X
License number
A169243 CA
Self-reported in NPPES; status is on the state search
Practice location
3285 Claremont Way, Napa, CA 94558
Phone
(707) 258-2500
Enumerated
Apr 4, 2017
Record last updated
Apr 12, 2022
Medicare enrollment
Enrolled (PECOS I20210406001612); accepts Medicare assignment
Medical or professional school
Florida International Univ, College Of Medicine, 2017
Telehealth
Offers telehealth (CMS)
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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8 nearest family medicine physician records → All 17,133 in California → Look up another NPI →

Also registered at 3285 Claremont Way

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Ernest Arras, MDInternal Medicine Physician1174601900
  2. Manuel Ballesca, MDInternal Medicine Physician1639257538
  3. Mary Ann Carol Besana, MDFamily Medicine Physician1700894540
  4. Donna Bodnar, MDObstetrics & Gynecology Physician1720166564
  5. Hilarie Chamberland, PHARM.D.Pharmacist1801940606
  6. James Cotter, MDFamily Medicine Physician1407934243

Verify William Dale Hasson in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A169243    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

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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43% more Medicare Part D claims than the average family medicine physician in 2024

5,068 Medicare Part D claims for 594 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. 306 claims were for opioids.

  1. William Hasson5,068
  2. Specialty average3,544

Most prescribed

  1. Atorvastatin Calcium435 claims
  2. Lisinopril227 claims
  3. Levothyroxine Sodium195 claims
  4. Losartan Potassium182 claims
  5. Amlodipine Besylate161 claims
  6. Hydrocodone-Acetaminophen160 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. Permanente Medical Group IncNapa, CA

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

William Dale Hasson among 17,133 family medicine physician records in California

William Dale Hasson, 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 2017, is newer than 79% of them.

  • NPI issued2017 · 79% of these records are older, 18% newer
  • In a Medicare fileYes · 81% of these records are
  • In the CMS Doctors and Clinicians fileYes · 62% of these records are
  • Graduated2017 · median 2005 among the 10,652 with a school on file
  • Record last updated2022 · 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).

59 family medicine physician records list a practice address in Napa

They are 59 of the 3,583 NPPES records with a practice address in Napa, and 17,133 family medicine physician records in California.

All 17,133 in California → Every provider in Napa → Family Medicine Physician nationwide →

The 8 family medicine physician records with the nearest ZIP codes

  1. Aurelio Campos, MDNapa, CA 945581265446280
  2. Andrea Clarke, MDNapa, CA 945581598734709
  3. Alexandre De Moraes, M.D.Napa, CA 945581942284831
  4. Benjamin Jewell, MDNapa, CA 945581134134091
  5. Federico Leon, M.D.Napa, CA 945581659349173
  6. Maria Montenegro, M.D.Napa, CA 945581992719199
  7. Robert Moore, MDNapa, CA 945581538194899
  8. Michael Novak, MDNapa, CA 945581972501179

Common questions

What is William Dale Hasson, M.D.'s NPI number?

William Dale Hasson, M.D.'s National Provider Identifier (NPI) is 1235662677, issued on Apr 4, 2017. An NPI identifies a provider in billing; it is not a license.

Where is William Dale Hasson, M.D. located?

The NPPES record lists a practice address at 3285 Claremont Way, Napa, CA, 94558. Phone: (707) 258-2500. Providers update this record themselves, so call before visiting.

How can I verify William Dale Hasson, M.D.'s license?

NPPES lists California license number A169243, 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 William Dale Hasson, M.D. prescribe under Medicare Part D?

In 2024, William Dale Hasson, M.D. had 5,068 Medicare Part D claims for 594 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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.