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

Dr. John Peter Czaja, O.D.

Optometrist in Merrillville, IN · enumerated 2010 · practices at John P Czaja Od PC.

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

National Provider Identifier

1679883912

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Registry record

Entity type Individual (Type 1)
Name Dr. John Peter Czaja
Credential O.D.
Sex Male
Practice address Merrillville, IN, 46410
Phone (219) 769-2020
Fax (219) 756-8937
Enumeration date Oct 20, 2010
Last updated in NPPES Oct 20, 2010

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 18002875A (IN) 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
200866690A 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.

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Frequently asked questions

What is the NPI number for John Czaja?
The National Provider Identifier (NPI) for John Czaja is 1679883912, a Type 1 (individual) record in the CMS NPPES registry.
Where does John Czaja practice?
The practice location on file with NPPES is in Merrillville, IN. Providers can have multiple locations; NPPES lists the primary practice address.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2010-10-20.