Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Theresa Clark Williamson, PT

Physical Therapist in San Jose, CA · enumerated 2005.

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

National Provider Identifier

1558344341

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Registry record

Entity type Individual (Type 1)

Name Theresa Clark Williamson

Credential PT

Sex Female

Practice address 1688 Willow St, Suite K, San Jose, CA, 95125

Phone (408) 264-6643

Fax (408) 264-6652

Enumeration date Nov 25, 2005

Last updated in NPPES Jul 13, 2026

Taxonomy & licenses

225100000X Physical Therapist Respiratory, Developmental, Rehabilitative and Restorative Service Providers · License PT 12383 (CA) Primary

PT · Physical Therapist: A licensed movement specialist treating injury and disability through exercise and rehabilitation. About the PT 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.

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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 Theresa Williamson?

Theresa Williamson is registered in NPPES with the primary taxonomy of Physical Therapist. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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