Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Christopher S Diehl, O.D.

Optometrist in Sioux City, IA · enumerated 2011.

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

National Provider Identifier

1053607515

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Registry record

Entity type Individual (Type 1)

Name Christopher S Diehl

Credential O.D.

Sex Male

Practice address 4405 Hamilton Blvd, Sioux City, IA, 51104

Phone (712) 239-3937

Enumeration date Jun 23, 2011

Last updated in NPPES Oct 4, 2021

Taxonomy & licenses

152W00000X Optometrist Eye and Vision Services Providers · License 002527 (IA) 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
1053607515	Medicaid	IA	-

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 Christopher Diehl?

Christopher Diehl is registered in NPPES with the primary taxonomy of Optometrist. 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 2021-10-04.