Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. William Peter Hansen, DDS

Dentist in Palo Alto, CA · enumerated 2006.

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

National Provider Identifier

1538271713

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Registry record

Entity type Individual (Type 1)

Name Dr. William Peter Hansen

Credential DDS

Sex Male

Practice address 1691 El Camino Real, Suite 200, Palo Alto, CA, 94306

Phone (650) 324-1292

Fax (650) 618-1944

Enumeration date Aug 31, 2006

Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

122300000X Dentist Dental Providers · License 22073 (CA) Primary

DDS · Doctor of Dental Surgery: A licensed dentist; DDS and DMD are equivalent dental degrees. About the DDS 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 William Hansen?

William Hansen is registered in NPPES with the primary taxonomy of Dentist. 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 2007-07-08.