NPI Portal NPI Lookup & Verification

Greg Williamson

Greg Williamson is a Behavior Analyst provider (Behavior Analyst) practicing in Manhattan Beach, CA, registered in the NPPES registry with NPI 1902463359 since 2019.

✓ Active NPI ✓ Valid NPI checksum Sole proprietor

NPI 1902463359
Entity type Individual (Type 1)
Name Greg Williamson
Sex Male
Practice address Manhattan Beach, CA, 90266
Phone 3104061500
Enumeration date 2019-05-21
Last updated in NPPES 2019-05-21

Street address withheld — NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

Taxonomy code Specialty Primary License State
103K00000X Behavior Analyst Primary
Copy-ready billing details
Provider: Greg Williamson
NPI: 1902463359
Taxonomy: 103K00000X (Behavior Analyst)
Address: Manhattan Beach, CA, 90266

Other providers at this practice address

NPI Name Type Specialty Location
1508233388 Deborah Sanders Individual Behavior Analyst Manhattan Beach, CA
1679937320 Thomas Vanmarter Individual Behavior Analyst Manhattan Beach, CA
1417489204 Andrew Frisina Individual Behavior Analyst Manhattan Beach, CA
1184130114 Maira Sandoval Individual Behavior Technician Manhattan Beach, CA
1851807861 Denise Vo Individual Behavior Technician Manhattan Beach, CA
1942717061 Kody Harms Individual Behavior Technician Manhattan Beach, CA
1750899720 Carlo Farrales Individual Behavior Technician Manhattan Beach, CA
1770091589 Efrain Gonzalez Individual Behavior Analyst Manhattan Beach, CA

Verify this record

Cross-check NPI 1902463359 against the authoritative CMS record: view Greg Williamson on the official NPPES registry .

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. Read the full guide or validate an NPI number.

Frequently asked questions

Is this the official NPI registry?
No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.
What specialty is Greg Williamson?
Greg Williamson is registered in NPPES with the primary taxonomy of Behavior Analyst. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2019-05-21.