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

John P Williams, D.O.

Internal Medicine Physician in Willits, CA · enumerated 2005.

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

National Provider Identifier

1144220369

Verified

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Registry record

Entity type Individual (Type 1)

Name John P Williams

Credential D.O.

Sex Male

Practice address Willits, CA, 95490

Phone (707) 459-5585

Fax (707) 459-3548

Enumeration date Jul 29, 2005

Last updated in NPPES Dec 19, 2018

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

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 20A6027 (CA) Primary

DO · Doctor of Osteopathic Medicine: A fully licensed physician trained in osteopathic medical schools, with the same practice rights as an MD. About the DO credential

Other identifiers

Identifier	Type	State	Issuer
00AX60271	Medicaid	CA	-
020A60270	Other	CA	BLUE SHIELD PROVIDER #
110228689	Other	CA	RAILROAD MEDICARE
20A6027	Other	CA	BLUE CROSS PROVIDER #

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

Where does John Williams practice?

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

What is the NPI number for John Williams?

The National Provider Identifier (NPI) for John Williams is 1144220369, a Type 1 (individual) record in the CMS NPPES registry.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2018-12-19.