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

William Alan Kocsis, MD

Individual provider Internal Medicine Physician · NPI 1225078280

William Alan Kocsis, MD is an Internal Medicine Physician in Napa, California. Licensed in California. Registered with an NPI since 2006.

Licensed in
CA
In the registry since
2006
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

2100 Napa-Vallejo Hwy
Napa, CA 94558-6293
Phone: (707) 253-5000
Fax: (707) 253-5513
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence G48474 (CA)

Record details

NPI number1225078280
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJune 7, 2006
Last updated in NPPESJuly 13, 2026

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