Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Callisyn Zielenski

Social Worker in San Francisco, CA · enumerated 2016.

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

National Provider Identifier

1861945461

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Registry record

Entity type Individual (Type 1)

Name Callisyn Zielenski

Sex Female

Practice address 3450 3rd St Ste 1c, San Francisco, CA, 94124

Phone (154) 437-3990

Enumeration date Jul 29, 2016

Last updated in NPPES Jul 10, 2026

Taxonomy & licenses

104100000X Social Worker Behavioral Health & Social Service Providers · License 125791 (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.

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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 Callisyn Zielenski?

Callisyn Zielenski is registered in NPPES with the primary taxonomy of Social Worker. 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 2026-07-10.