Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

DR. WILLIAM G ANNAN MD
NPI 1124010384
Specialist in Garden Grove, CA

Q: What is William Annan's NPI number?

The NPI number for William Annan is 1124010384. It was assigned to this individual provider in the NPPES registry on August 15, 2005.

Q: What is William Annan's specialty?

The primary specialty registered for this NPI is Specialist with taxonomy code 174400000X.

Q: When was this NPI record last updated?

The NPPES record for William Annan was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 26 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since August 15, 2005

12555 GARDEN GROVE BLVD, SUITE 302, GARDEN GROVE, CA 92843(714) 530-3270(714) 530-3278 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 02, 2026.

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About Dr. William G Annan Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. WILLIAM G ANNAN MD (NPI 1124010384) is an individual specialist in Garden Grove, California, licensed in California (G13787) and active in the NPI registry since August 2005.

NPPES Registry Identity

NPI1124010384

Entity TypeIndividualMale

Primary Taxonomy174400000X

Provider Legal NameDR. WILLIAM G ANNANCredential: MD

Location Address12555 GARDEN GROVE BLVD, SUITE 302Garden Grove, CA 92843-1902

Mailing Address12555 Garden Grove Blvd, Suite 302Garden Grove, CA 92843-1902 · (714) 530-3270 · Fax (714) 530-3278

Phone(714) 530-3270

Fax(714) 530-3278

Sole ProprietorNo

Enumeration DateAugust 15, 2005

Last NPPES UpdateJuly 13, 2026

✔ NPI 1124010384 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySpecialistOther Service Providers

Taxonomy Code174400000X

License✔ Licensed in CA · G13787

Definition

An individual educated and trained in an applied knowledge discipline used in the performance of work at a level requiring knowledge and skills beyond or apart from that provided by a general education or liberal arts degree.

12555 GARDEN GROVE BLVD, Garden Grove, CA 92843

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Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

ANDREW H AHN MD PROFESSIONAL CORPORATION

Surgery (Vascular Surgery)

12555 GARDEN GROVE BLVD, SUITE 403
GARDEN GROVE, CA 92843

Orange County (714) 530-0303

PUNEET K CHAHAL, M.D. INC

Internal Medicine (Infectious Disease)

12555 GARDEN GROVE BLVD, #405
GARDEN GROVE, CA 92843

Orange County (714) 530-8042

DR. RAMAN CHOPRA MD

Pediatrics

12555 GARDEN GROVE BLVD, SUITE 404
GARDEN GROVE, CA 92843

Orange County (714) 638-0232

MICHAEL S FINNEY M.D.

Internal Medicine (Infectious Disease)

12555 GARDEN GROVE BLVD, STE 405
GARDEN GROVE, CA 92843

Orange County (714) 530-8042

MS. SAADIA PAREKH PA-C

Physician Assistant

12555 GARDEN GROVE BLVD, #206
GARDEN GROVE, CA 92843

Orange County (714) 537-6595

JANAK R. CHOPRA M.D.INC.

Clinic/Center

12555 GARDEN GROVE BLVD, #404
GARDEN GROVE, CA 92843

Orange County (714) 638-0232

RAI CARE CENTERS OF SOUTHERN CALIFORNIA I, LLC

Clinic/Center (End-Stage Renal Disease (ESRD) Treatment)

12555 GARDEN GROVE BLVD, SUITE 100
GARDEN GROVE, CA 92843

Orange County (714) 741-7255

DR. HONG-AN JAN M.D.

Specialist

12555 GARDEN GROVE BLVD, SUITE 202
GARDEN GROVE, CA 92843

Orange County (714) 538-1288

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is William Annan's NPI number?

The NPI number for William Annan is 1124010384. It was assigned to this individual provider in the NPPES registry on August 15, 2005.

Where is William Annan located?

William Annan practices at 12555 Garden Grove Blvd Suite 302, Garden Grove, CA 92843. The listed phone number is (714) 530-3270.

What is William Annan's specialty?

The primary specialty registered for this NPI is Specialist with taxonomy code 174400000X.

When was this NPI record last updated?

The NPPES record for William Annan was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 26 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.