Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Alison Williams, MSW, PPSC

Social Worker in San Lorenzo, CA · enumerated 2017.

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

National Provider Identifier

1598287294

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Registry record

Entity type Individual (Type 1)

Name Alison Williams

Credential MSW, PPSC

Sex Female

Practice address 50 E Lewelling Blvd, San Lorenzo, CA, 94580

Phone (510) 273-4700

Enumeration date Jul 13, 2017

Last updated in NPPES Dec 16, 2019

Taxonomy & licenses

101YM0800X Mental Health Counselor Behavioral Health & Social Service Providers Secondary

1041S0200X School Social Worker Behavioral Health & Social Service Providers Secondary

390200000X Student in an Organized Health Care Education/Training Program Student, Health Care Secondary

104100000X Social Worker Behavioral Health & Social Service Providers · License 78772 (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 is the NPI number for Alison Williams?

The National Provider Identifier (NPI) for Alison Williams is 1598287294, a Type 1 (individual) record in the CMS NPPES registry.

Where does Alison Williams practice?

The practice location on file with NPPES is in San Lorenzo, CA. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

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Amy Halio Pediatrics Physician · San Lorenzo, CA NPI 1780699538 Harjindar Lally Social Worker · San Lorenzo, CA NPI 1245470772 La Clinica De La Raza, Inc. Federally Qualified Health Center (FQHC) · San Lorenzo, CA NPI 1316188543 Nadia Arce-Fernandez Clinical Social Worker · San Lorenzo, CA NPI 1851688444 Frances Delgadillo Clinical Social Worker · San Lorenzo, CA NPI 1568134278 Elizabeth Gonzalez Pediatric Nurse Practitioner · San Lorenzo, CA NPI 1487373072 Seneca Family of Agencies Community/Behavioral Health Agency · Ashland, CA NPI 1568346054 Carly Jespersen Speech-Language Pathologist · Ashland, CA NPI 1912859810

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2019-12-16.