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

Dr. Gideon Albert Letz, M.D.

Preventive Medicine/Occupational Environmental Medicine Physician in San Francisco, CA · enumerated 2007.

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

National Provider Identifier

1942356233

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Registry record

Entity type Individual (Type 1)

Name Dr. Gideon Albert Letz

Credential M.D.

Sex Male

Practice address San Francisco, CA, 94103

Phone (415) 565-1677

Fax (415) 581-8044

Enumeration date Jan 27, 2007

Last updated in NPPES Jul 8, 2007

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

Taxonomy & licenses

2083P0500X Preventive Medicine/Occupational Environmental Medicine Physician Allopathic & Osteopathic Physicians · License G35503 (CA) Primary

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
M193827	Other	-	NUID

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

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 Gideon Letz?

Gideon Letz is registered in NPPES with the primary taxonomy of Preventive Medicine/Occupational Environmental Medicine 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 2007-07-08.