Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Alexander Constantine Tzanos, D.D.S.

Periodontics in Crystal Lake, IL · enumerated 2008.

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

National Provider Identifier

1821250630

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Registry record

Entity type Individual (Type 1)

Name Dr. Alexander Constantine Tzanos

Credential D.D.S.

Sex Male

Practice address 411 E Congress Pkwy Ste D, Crystal Lake, IL, 60014

Phone (814) 455-6550

Enumeration date Jul 2, 2008

Last updated in NPPES May 28, 2021

Taxonomy & licenses

1223P0300X Periodontics Dental Providers · License 019027377 (IL) Primary

DDS · Doctor of Dental Surgery: A licensed dentist; DDS and DMD are equivalent dental degrees. About the DDS 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.

Read the full guide → Validate an NPI →

Frequently asked questions

What is the NPI number for Alexander Tzanos?

The National Provider Identifier (NPI) for Alexander Tzanos is 1821250630, a Type 1 (individual) record in the CMS NPPES registry.

Where does Alexander Tzanos practice?

The practice location on file with NPPES is in Crystal Lake, IL. Providers can have multiple locations; NPPES lists the primary practice address.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2021-05-28.