NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Mr. Donald L. Tressler, PA-C

Medical Physician Assistant in Middleburg, PA · enumerated 2006.

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

National Provider Identifier

1518915107

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Registry record

Entity type Individual (Type 1)
Name Mr. Donald L. Tressler
Credential PA-C
Sex Male
Practice address Middleburg, PA, 17842
Phone (570) 837-2123
Fax (570) 837-2185
Enumeration date May 5, 2006
Last updated in NPPES Dec 30, 2008

Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

363A00000X Physician Assistant Physician Assistants & Advanced Practice Nursing Providers · License OA002220 (PA) Secondary
363AM0700X Medical Physician Assistant Physician Assistants & Advanced Practice Nursing Providers · License MA051971 (PA) Primary

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.

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Frequently asked questions

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.
What specialty is Donald Tressler?
Donald Tressler is registered in NPPES with the primary taxonomy of Medical Physician Assistant. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2008-12-30.