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William S Baek, M.D..

Neurology Physician in Upland, CA · enumerated 2006.

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

National Provider Identifier

1326095977

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Registry record

Entity type Individual (Type 1)
Name William S Baek
Credential M.D..
Sex Male
Practice address 630 N 13th Ave, Suite B, Upland, CA, 91786
Phone (909) 982-2719
Fax (909) 946-9931
Enumeration date May 28, 2006
Last updated in NPPES Feb 6, 2012

Taxonomy & licenses

2084N0400X Neurology Physician Allopathic & Osteopathic Physicians · License A91283 (CA) Primary
MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

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 William Baek?
William Baek is registered in NPPES with the primary taxonomy of Neurology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2012-02-06.