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

Dr. Cesar Enrique Siu, O.D.

Optometrist in Union City, CA · enumerated 2007 · practices at Leonard S. Chong, D.D.S., Inc..

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

National Provider Identifier

1699821967

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Registry record

Entity type Individual (Type 1)
Name Dr. Cesar Enrique Siu
Credential O.D.
Sex Male
Practice address Union City, CA, 94587
Phone (510) 487-5856
Fax (510) 487-3772
Enumeration date Jan 26, 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

152W00000X Optometrist Eye and Vision Services Providers · License 8860T (CA) Primary
OD · Doctor of Optometry: A licensed optometrist providing primary vision care, eye exams, and corrective lenses. About the OD credential

Other identifiers

Identifier Type State Issuer
SD0088600 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 1699821967 active?
Yes, as of the latest NPPES snapshot, NPI 1699821967 is active (record last updated 2007-07-08).
How do I verify Cesar Siu's NPI record?
Cross-check NPI 1699821967 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.