Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. William G Annan, MD

Specialist in Garden Grove, CA · enumerated 2005.

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

National Provider Identifier

1124010384

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Registry record

Entity type Individual (Type 1)

Name Dr. William G Annan

Credential MD

Sex Male

Practice address 12555 Garden Grove Blvd, Suite 302, Garden Grove, CA, 92843

Phone (714) 530-3270

Fax (714) 530-3278

Enumeration date Aug 15, 2005

Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

174400000X Specialist Other Service Providers · License G13787 (CA) Primary

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

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 William Annan?

The National Provider Identifier (NPI) for William Annan is 1124010384, a Type 1 (individual) record in the CMS NPPES registry.

Where does William Annan practice?

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

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.