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

William Sherwin

Marriage & Family Therapist in Rancho Santa Margarita, CA · enumerated 2008.

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

National Provider Identifier

1780848374

Verified

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Registry record

Entity type Individual (Type 1)

Name William Sherwin

Sex Male

Practice address Rancho Santa Margarita, CA, 92688

Phone (415) 940-5221

Enumeration date Jul 14, 2008

Last updated in NPPES Sep 25, 2025

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

Taxonomy & licenses

106H00000X Marriage & Family Therapist Behavioral Health & Social Service Providers · License 49178 (CA) 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.

Read the full guide → Validate an NPI →

Frequently asked questions

What specialty is William Sherwin?

William Sherwin is registered in NPPES with the primary taxonomy of Marriage & Family Therapist. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-09-25.