Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Michael Joseph Williams, M.D.

Diagnostic Radiology Physician in Santa Rosa, CA · enumerated 2006.

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

National Provider Identifier

1609956465

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Registry record

Entity type Individual (Type 1)

Name Michael Joseph Williams

Credential M.D.

Sex Male

Practice address 121 Sotoyome St, Santa Rosa, CA, 95405

Phone (707) 546-4062

Fax (707) 525-4097

Enumeration date Oct 16, 2006

Last updated in NPPES Jun 10, 2014

Taxonomy & licenses

2085N0904X Nuclear Radiology Physician Allopathic & Osteopathic Physicians · License G49905 (CA) Secondary

2085B0100X Body Imaging Physician Allopathic & Osteopathic Physicians · License G49905 (CA) Secondary

2085R0202X Diagnostic Radiology Physician Allopathic & Osteopathic Physicians · License G49905 (CA) Primary

2085U0001X Diagnostic Ultrasound Physician Allopathic & Osteopathic Physicians · License G49905 (CA) Secondary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier	Type	State	Issuer
00G499050	Medicaid	CA	-

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 Michael Williams practice?

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

What is the NPI number for Michael Williams?

The National Provider Identifier (NPI) for Michael Williams is 1609956465, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2014-06-10.