MARY KATHERINE KOSOWSKI, A-GNP-C appears in the CMS NPPES registry as a Adult Health Nurse Practitioner provider holding A-GNP-C credentials at 600 HARLEM RD, WEST SENECA, NY, 14224, with a listed phone of (716) 332-2121. NPI 1558937441 was issued on 06/01/2021. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what KOSOWSKI most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 3,603 prescription claims written by this provider, covering 774 Medicare beneficiaries and totaling roughly $2.0 million in drug spend, split 51% brand-name and 49% generic by claim count. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Adult Health Nurse Practitioner is a mid-sized specialty nationwide, with 29,492 enrolled providers across 55 states and an average of 1,201 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.