Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Marissa L. Williamson, BCBA

Behavior Analyst in Thousand Oaks, CA · enumerated 2010.

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

National Provider Identifier

1942512496

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Registry record

Entity type Individual (Type 1)

Name Marissa L. Williamson

Credential BCBA

Sex Female

Practice address Thousand Oaks, CA, 91360

Phone (877) 262-9133

Fax (877) 262-9134

Enumeration date Jul 12, 2010

Last updated in NPPES Jul 12, 2010

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

Taxonomy & licenses

103K00000X Behavior Analyst Behavioral Health & Social Service Providers · License 1-09-6790 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

How do I verify Marissa Williamson's NPI record?

Cross-check NPI 1942512496 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Is NPI 1942512496 active?

Yes, as of the latest NPPES snapshot, NPI 1942512496 is active (record last updated 2010-07-12).

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2010-07-12.