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

Dr. Jack D Williamson, LCSW

Clinical Social Worker in Lakewood, WA · enumerated 2009.

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

National Provider Identifier

1134363666

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Registry record

Entity type Individual (Type 1)

Name Dr. Jack D Williamson

Credential LCSW

Sex Male

Practice address Lakewood, WA, 98499

Phone (253) 476-1234

Enumeration date Apr 28, 2009

Last updated in NPPES Apr 28, 2009

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

Taxonomy & licenses

1041C0700X Clinical Social Worker Behavioral Health & Social Service Providers · License LW00006358 (WA) Primary

LCSW · Licensed Clinical Social Worker: A social worker licensed for clinical practice including mental-health therapy. About the LCSW credential

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 → Validate an NPI →

Frequently asked questions

What is the NPI number for Jack Williamson?

The National Provider Identifier (NPI) for Jack Williamson is 1134363666, a Type 1 (individual) record in the CMS NPPES registry.

Where does Jack Williamson practice?

The practice location on file with NPPES is in Lakewood, WA. Providers can have multiple locations; NPPES lists the primary practice address.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2009-04-28.