Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mr. Geoffrey Michael Simkins, MSW

Clinical Social Worker in Mukilteo, WA · enumerated 2013 · practices at Mastery Mental Health Pllc.

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

National Provider Identifier

1568703551

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Registry record

Entity type Individual (Type 1)

Name Mr. Geoffrey Michael Simkins

Credential MSW

Sex Male

Practice address 627 5th St Ste 200, Mukilteo, WA, 98275

Phone (206) 309-3839

Fax (425) 513-2329

Enumeration date Mar 15, 2013

Last updated in NPPES Oct 26, 2020

Taxonomy & licenses

1041C0700X Clinical Social Worker Behavioral Health & Social Service Providers · License SC60341239 (WA) Primary

101Y00000X Counselor Behavioral Health & Social Service Providers · License SC60341239 (WA) Secondary

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 Geoffrey Simkins?

Geoffrey Simkins is registered in NPPES with the primary taxonomy of Clinical Social Worker. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Mastery Mental Health Pllc Clinical Social Worker · Mukilteo, WA NPI 1356942064

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2020-10-26.