Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Donald Gary Williams

Addiction (Substance Use Disorder) Counselor in San Marcos, CA · enumerated 2018.

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

National Provider Identifier

1073001210

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Donald Gary Williams

Sex Male

Practice address 1560 Capalina Rd, San Marcos, CA, 92069

Phone (760) 744-2104

Enumeration date Apr 24, 2018

Last updated in NPPES Apr 24, 2018

Taxonomy & licenses

101YA0400X Addiction (Substance Use Disorder) Counselor Behavioral Health & Social Service Providers · License AO22580316 (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 Donald Williams?

The National Provider Identifier (NPI) for Donald Williams is 1073001210, a Type 1 (individual) record in the CMS NPPES registry.

Where does Donald Williams practice?

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

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2018-04-24.