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

Dr. Leon J. Kosek, O.D.

Optometrist in Frankfort, IL · enumerated 2006 · practices at Meus Family Vision Care LLC.

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

National Provider Identifier

1801834080

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Registry record

Entity type Individual (Type 1)

Name Dr. Leon J. Kosek

Credential O.D.

Sex Male

Practice address Frankfort, IL, 60423

Phone (815) 469-8541

Fax (815) 469-8126

Enumeration date Jun 2, 2006

Last updated in NPPES Jul 6, 2011

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 18001974A (IN) Secondary

152W00000X Optometrist Eye and Vision Services Providers · License 046007472 (IL) 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
100086900A	Medicaid	IN	-

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.

Read the full guide → Validate an NPI →

Frequently asked questions

What specialty is Leon Kosek?

Leon Kosek 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.

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.

Other providers at this practice address

Browse all →

Judith Walsh Optometrist · Frankfort, IL NPI 1548368632 Meus Family Vision Care LLC Optometrist · Frankfort, IL NPI 1649904350

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-07-06.