Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Dr. William Dale Hasson II, MD

Individual provider Family Medicine Physician · NPI 1235662677

Dr. William Dale Hasson II, MD is registered under Family Practice in Napa, California. Graduated from Florida International Univ, College of Medicine in 2017, 9 years ago. Practices with Permanente Medical Group Inc, a 10,941-clinician group, accepts Medicare assignment and offers telehealth. Licensed in California.

Years since qualifying
9
Trained at
Florida International Univ, College of Medicine
Licensed in
CA
In the registry since
2017
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

3285 Claremont Way
Napa, CA 94558-3313
Phone: (707) 258-2500
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Family Medicine Physician (primary) Taxonomy 207Q00000X · Licence A169243 (CA)

Record details

NPI number1235662677
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedApril 4, 2017
Last updated in NPPESApril 12, 2022
Certification dateApril 12, 2022

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyFAMILY PRACTICE
Medical schoolFLORIDA INTERNATIONAL UNIV, COLLEGE OF MEDICINE
Graduated 2017 (9 years in practice)
Group practice Permanente Medical Group Inc — 10941 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients13
Services billed 21 a service is one billed item, such as a visit, a test or a procedure
Average patient age68

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Colleagues at Permanente Medical Group Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 10941 clinicians in the practice; 12 are shown here.

Other providers in Napa