NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Mark William Hartzler, DMD

General Practice Dentistry in Gorham, NH · enumerated 2012 · practices at Paul C Schoenbeck, Dmd., PA.

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

National Provider Identifier

1215287271

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)
Name Dr. Mark William Hartzler
Credential DMD
Sex Male
Practice address 22 Exchange St, Gorham, NH, 03581
Phone (603) 466-5015
Enumeration date Sep 17, 2012
Last updated in NPPES Jan 3, 2013

Taxonomy & licenses

1223G0001X General Practice Dentistry Dental Providers · License DN1856094 (MA) Secondary
1223G0001X General Practice Dentistry Dental Providers · License 03961 (NH) Primary
DMD · Doctor of Medicine in Dentistry: A licensed dentist; DMD and DDS are equivalent dental degrees. About the DMD 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

Is NPI 1215287271 active?
Yes, as of the latest NPPES snapshot, NPI 1215287271 is active (record last updated 2013-01-03).
How do I verify Mark Hartzler's NPI record?
Cross-check NPI 1215287271 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-01-03.