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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

GREGORY V SIERMINSKI DDS
NPI 1255386801
Dentist in Wonder Lake, IL

Active since May 23, 2006
7442 HANCOCK DR, WONDER LAKE, IL 60097(815) 728-0100(815) 728-0114 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 16, 2026.

About Gregory V Sierminski Dds NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

GREGORY V SIERMINSKI DDS (NPI 1255386801) is an individual dentist in Wonder Lake, Illinois, licensed in Illinois (19015910) and active in the NPI registry since May 2006.

NPPES Registry Identity

NPI1255386801
Entity TypeIndividualMale
Primary Taxonomy122300000X
Provider Legal NameGREGORY V SIERMINSKICredential: DDS
Location Address7442 HANCOCK DRWonder Lake, IL 60097
Mailing Address7442 Hancock DrWonder Lake, IL 60097 · (815) 728-0100 · Fax (815) 728-0114
Phone(815) 728-0100
Fax(815) 728-0114
Sole ProprietorNo
Enumeration DateMay 23, 2006
Last NPPES UpdateJuly 13, 2026
✔ NPI 1255386801 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyDentistDental Providers
Taxonomy Code122300000X
License✔ Licensed in IL · 19015910
Definition
A dentist is a person qualified by a doctorate in dental surgery (D.D.S.) or dental medicine (D.M.D.), licensed by the state to practice dentistry, and practicing within the scope of that license. There is no difference between the two degrees: dentists who have a DMD or DDS have the same education. Universities have the prerogative to determine what degree is awarded. Both degrees use the same curriculum requirements set by the American Dental Association's Commission on Dental Accreditation. Generally, three or more years of undergraduate education plus four years of dental school is required to graduate and become a general dentist. State licensing boards accept either degree as equivalent, and both degrees allow licensed individuals to practice the same scope of general dentistry. Additional post-graduate training is required to become a dental specialist.
7442 HANCOCK DR, Wonder Lake, IL 60097
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Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Gregory Sierminski's NPI number?

The NPI number for Gregory Sierminski is 1255386801. It was assigned to this individual provider in the NPPES registry on May 23, 2006.

Where is Gregory Sierminski located?

Gregory Sierminski practices at 7442 Hancock Dr, Wonder Lake, IL 60097. The listed phone number is (815) 728-0100.

What is Gregory Sierminski's specialty?

The primary specialty registered for this NPI is Dentist with taxonomy code 122300000X.

When was this NPI record last updated?

The NPPES record for Gregory Sierminski was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 36 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.