William Sia, NP-C
NPI 1679063945 · Family Nurse Practitioner · Upland, CA
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Sia, NP-C is a Family Nurse Practitioner provider in Upland, CA (NPI 1679063945).
Provider details
- NPI number
- 1679063945
- Entity type
- Individual
- Primary specialty
- Family Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- NP-C
- Sex
- Male
- Sole proprietor
- No
- License
- F03180293 (CA)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
8 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2018-05-13
- Last updated
- 2019-09-12
Frequently asked questions
- What is William Sia's NPI number?
- William Sia's National Provider Identifier (NPI) is 1679063945, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Sia's specialty?
- William Sia is listed in the NPPES registry with a primary specialty of Family Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is William Sia located?
- William Sia's practice location on file with NPPES is 1382 E Foothill Blvd, Upland, CA 91786-4014.
- What is William Sia's phone number?
- The practice phone number listed in the NPPES registry for William Sia is (909) 982-6500.
- Does William Sia accept Medicare?
- William Sia is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Sia's NPI active?
- Yes — William Sia's NPI (1679063945) is active in the NPPES registry as of the last update on 2019-09-12.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.