John D Siekmann, DDS
John D Siekmann is a Dentist provider (Dentist) practicing in Gurnee, IL, registered in the NPPES registry with NPI 1336240191 since 2006. The credential DDS stands for Doctor of Dental Surgery.
✓ Active NPI ✓ Valid NPI checksum
| NPI | 1336240191 |
|---|---|
| Entity type | Individual (Type 1) |
| Name | John D Siekmann |
| Credential | DDS |
| Sex | Male |
| Practice address | 101 S GREENLEAF ST, SUITE E, Gurnee, IL, 60031 |
| Phone | 8476623100 |
| Fax | 8476623125 |
| Enumeration date | 2006-09-26 |
| Last updated in NPPES | 2007-07-08 |
Taxonomy & licenses
| Taxonomy code | Specialty | Primary | License | State |
|---|---|---|---|---|
| 122300000X | Dentist | Primary | — | IL |
DDS — Doctor of Dental Surgery: A licensed dentist; DDS and DMD are equivalent dental degrees. About the DDS credential
Copy-ready billing details
Provider: John Siekmann, DDS NPI: 1336240191 Taxonomy: 122300000X (Dentist) Address: 101 S GREENLEAF ST, SUITE E, Gurnee, IL, 60031
Other providers at this practice address
| NPI | Name | Type | Specialty | Location |
|---|---|---|---|---|
| 1780662254 | Walid Ghantous | Individual | Nephrology Physician | Gurnee, IL |
| 1518073444 | National Medical Care Inc | Organization | End-Stage Renal Disease (ESRD) Treatment Clinic/Center | Gurnee, IL |
| 1831206366 | Associates for Family Dentistry, Ltd | Organization | General Practice Dentistry | Gurnee, IL |
| 1649371410 | Ross Johnsen | Individual | Dentist | Gurnee, IL |
| 1235230012 | Dennis Dobrin | Individual | Dentist | Gurnee, IL |
| 1376644112 | William Dobrin | Individual | Dentist | Gurnee, IL |
| 1881795656 | Duc Chung | Individual | Dentist | Gurnee, IL |
| 1346341138 | Matthew Tobkin | Individual | Dentist | Gurnee, IL |
Verify this record
Cross-check NPI 1336240191 against the authoritative CMS record: view John D Siekmann on the official NPPES registry .
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 or validate an NPI number.
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Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2007-07-08.