Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Gregg Duistermars, O.D.
Optometrist in Granbury, TX · enumerated 2007.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1376696427
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Registry record
Entity type Individual (Type 1)
Name Gregg Duistermars
Credential O.D.
Sex Male
Practice address 1201 Medical Plaza Ct, Granbury, TX, 76048
Phone (817) 279-9044
Fax (817) 573-6234
Enumeration date Jan 20, 2007
Last updated in NPPES Aug 20, 2013
Taxonomy & licenses
OD · Doctor of Optometry: A licensed optometrist providing primary vision care, eye exams, and corrective lenses.
About the OD 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.
Frequently asked questions
Is NPI 1376696427 active?
Yes, as of the latest NPPES snapshot, NPI 1376696427 is active (record last updated 2013-08-20).
How do I verify Gregg Duistermars's NPI record?
Cross-check NPI 1376696427 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 → Shannon Mueller Foot & Ankle Surgery Podiatrist · Granbury, TX NPI 1528066255 Brazos Foot and Ankle Clinic P.A. Podiatrist · Granbury, TX NPI 1851399893 Nicole Mueller Ophthalmology Physician · Granbury, TX NPI 1992703789 Nicole A. Mueller P.A. Ophthalmology Physician · Granbury, TX NPI 1861491037 Nancy Cox Optometrist · Granbury, TX NPI 1376064998
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-08-20.