Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Dr. William J Kowalski, DMD MS
Endodontics in Fenton, MO · enumerated 2006.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1114090842
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Registry record
Entity type Individual (Type 1)
Name Dr. William J Kowalski
Credential DMD MS
Sex Male
Practice address 1568 Smizer Station Road, William J Kowalski Dmd Ms, Fenton, MO, 63026
Phone (636) 225-2330
Fax (636) 225-2335
Enumeration date Nov 17, 2006
Last updated in NPPES Jul 8, 2007
Taxonomy & licenses
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.
Frequently asked questions
What specialty is William Kowalski?
William Kowalski is registered in NPPES with the primary taxonomy of Endodontics. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
Is this the official NPI registry?
No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.