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Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Sam S Ahn, M.D.

Allergy & Immunology (Internal Medicine) Physician in Napa, CA · enumerated 2006.

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

National Provider Identifier

1558423814

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Registry record

Entity type Individual (Type 1)
Name Dr. Sam S Ahn
Credential M.D.
Sex Male
Practice address 1100 Pear Tree Ln, Napa, CA, 94558
Phone (707) 258-8100
Fax (707) 258-0734
Enumeration date Dec 14, 2006
Last updated in NPPES Mar 7, 2023

Taxonomy & licenses

207RA0201X Allergy & Immunology (Internal Medicine) Physician Allopathic & Osteopathic Physicians · License 147289 (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
147289 Other CA CA LICENSE
42933 Other AZ AZ LICENSE

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

How do I verify Sam Ahn's NPI record?
Cross-check NPI 1558423814 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.
Is NPI 1558423814 active?
Yes, as of the latest NPPES snapshot, NPI 1558423814 is active (record last updated 2023-03-07).

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2023-03-07.