Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Gregory V Sierminski, DDS, PC

Organization Dentist · NPI 1720259013

Gregory V Sierminski, DDS, PC is a Dentist in Crystal Lake, Illinois. Registered with an NPI since 2008.

In the registry since
2008
What do these letters mean?
PC — Professional corporation
A form of business registration, not a clinical qualification.

See every abbreviation used in this directory →

Practice location Address checks out

7442 Hancock Dr
Crystal Lake, IL 60097
Phone: (815) 728-0100
Fax: (815) 728-0114
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Dentist (primary) Taxonomy 122300000X

Record details

NPI number1720259013
Entity typeOrganization (Type 2)
Organization subpartNo
Authorized official Gregory Sierminski — Dentist · (815) 728-0100
NPI enumeratedMarch 14, 2008
Last updated in NPPESMarch 14, 2008
Mailing addressP.O. Box 388, Wonder Lake, IL 60097

Other providers in Crystal Lake