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Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Choon Sil Koo, M.D.

Anatomic Pathology & Clinical Pathology Physician in Upland, CA · enumerated 2005.

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

National Provider Identifier

1265427595

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Registry record

Entity type Individual (Type 1)
Name Choon Sil Koo
Credential M.D.
Sex Male
Practice address 999 San Bernardino Rd, Upland, CA, 91786
Phone (909) 985-2811
Fax (909) 920-3827
Enumeration date Sep 13, 2005
Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

207ZP0102X Anatomic Pathology & Clinical Pathology Physician Allopathic & Osteopathic Physicians · License A31561 (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
00A315610 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 NPI 1265427595 active?
Yes — as of the latest NPPES snapshot, NPI 1265427595 is active (record last updated 2007-07-08).
How do I verify Choon Koo's NPI record?
Cross-check NPI 1265427595 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

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