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

William A. Sia, NP-C

Individual provider Family Nurse Practitioner · NPI 1679063945

William A. Sia, NP-C is a Family Nurse Practitioner in Upland, California. Licensed in California. Registered with an NPI since 2018.

Licensed in
CA
In the registry since
2018
What do these letters mean?
NP-C — Nurse Practitioner, Certified
A nurse practitioner certified by the AANP.

See every abbreviation used in this directory →

Practice location Address checks out

1382 E Foothill Blvd
Upland, CA 91786-4014
Phone: (909) 982-6500
Fax: (909) 920-0406
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Family Nurse Practitioner (primary) Taxonomy 363LF0000X · Licence F03180293 (CA)

Record details

NPI number1679063945
Entity typeIndividual (Type 1)
GenderMale
Credentials NP-C
Sole proprietorNo
NPI enumeratedMay 13, 2018
Last updated in NPPESSeptember 12, 2019
Mailing address1365 Wickham Ct, San Dimas, CA 91773-3862

Other providers in Upland