Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Charles E. Irwin Jr., M.D.

Pediatrics Physician in San Francisco, CA · enumerated 2006.

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

National Provider Identifier

1700812005

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Registry record

Entity type Individual (Type 1)

Name Dr. Charles E. Irwin Jr.

Credential M.D.

Sex Male

Practice address Acc 400 Parnassus Ave. 2nd Fl., San Francisco, CA, 94143

Phone (415) 353-2002

Fax (415) 353-2466

Enumeration date Jun 25, 2006

Last updated in NPPES Sep 11, 2025

Taxonomy & licenses

208000000X Pediatrics Physician Allopathic & Osteopathic Physicians · License G23139 (CA) Primary

2080A0000X Pediatric Adolescent Medicine Physician Allopathic & Osteopathic Physicians · License G23139 (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
00G231390	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.

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Frequently asked questions

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

What specialty is Charles Irwin?

Charles Irwin is registered in NPPES with the primary taxonomy of Pediatrics Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-09-11.