Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
William Loo
Physician Assistant in Pomona, CA · enumerated 2024.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1427887660
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Registry record
Entity type Individual (Type 1)
Name William Loo
Sex Male
Practice address 450 E 2nd St, Pomona, CA, 91766
Phone (909) 469-5335
Enumeration date Jul 27, 2024
Last updated in NPPES Jan 16, 2025
Taxonomy & licenses
363A00000X Physician Assistant Physician Assistants & Advanced Practice Nursing Providers · License 65690 (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.
Frequently asked questions
What is the NPI number for William Loo?
The National Provider Identifier (NPI) for William Loo is 1427887660, a Type 1 (individual) record in the CMS NPPES registry.
Where does William Loo practice?
The practice location on file with NPPES is in Pomona, CA. Providers can have multiple locations; NPPES lists the primary practice address.
Other providers at this practice address
Browse all →Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-01-16.