Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mrs. Mary Katherine Kosowski, A-GNP-C

Adult Health Nurse Practitioner in West Seneca, NY · enumerated 2021 · practices at Buffalo Endocrinology, L.L.C..

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

National Provider Identifier

1558937441

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Registry record

Entity type Individual (Type 1)

Name Mrs. Mary Katherine Kosowski

Credential A-GNP-C

Sex Female

Practice address 600 Harlem Rd, West Seneca, NY, 14224

Phone (716) 332-2121

Fax (716) 332-2122

Enumeration date Jun 1, 2021

Last updated in NPPES Aug 28, 2025

Taxonomy & licenses

363LA2200X Adult Health Nurse Practitioner Physician Assistants & Advanced Practice Nursing Providers · License F309522-01 (NY) 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

Where does Mary Katherine Kosowski practice?

The practice location on file with NPPES is in West Seneca, NY. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Mary Katherine Kosowski?

The National Provider Identifier (NPI) for Mary Katherine Kosowski is 1558937441, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

Browse all →

Buffalo Endocrinology, L.L.C. Endocrinology, Diabetes & Metabolism Physician · West Seneca, NY NPI 1467406801 Patricia Parysek Family Nurse Practitioner · West Seneca, NY NPI 1205880770 Toni Murphy Endocrinology, Diabetes & Metabolism Physician · West Seneca, NY NPI 1003862897 Anne Marie Bantle Family Nurse Practitioner · West Seneca, NY NPI 1083044481 Daniel Plumeri Physician Assistant · Buffalo, NY NPI 1447767983 Raffaele Ruggiero Endocrinology, Diabetes & Metabolism Physician · West Seneca, NY NPI 1457814196 Katlyn Holt Physician Assistant · West Seneca, NY NPI 1902468275

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-08-28.