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William A. Sia, NP-C

Family Nurse Practitioner in Upland, CA · enumerated 2018.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1679063945

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Registry record

Entity type Individual (Type 1)
Name William A. Sia
Credential NP-C
Sex Male
Practice address 1382 E Foothill Blvd, Upland, CA, 91786
Phone (909) 982-6500
Fax (909) 920-0406
Enumeration date May 13, 2018
Last updated in NPPES Sep 12, 2019

Taxonomy & licenses

363LF0000X Family Nurse Practitioner Physician Assistants & Advanced Practice Nursing Providers · License F03180293 (CA) Primary

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

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Frequently asked questions

Where does William Sia practice?
The practice location on file with NPPES is in Upland, CA. Providers can have multiple locations; NPPES lists the primary practice address.
What is the NPI number for William Sia?
The National Provider Identifier (NPI) for William Sia is 1679063945, a Type 1 (individual) record in the CMS NPPES registry.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2019-09-12.