Mary Katherine Kosowski, A-GNP-C
NPI 1558937441 · Adult Health Nurse Practitioner · West Seneca, NY
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mary Katherine Kosowski, A-GNP-C is a Adult Health Nurse Practitioner provider in West Seneca, NY (NPI 1558937441).
Provider details
- NPI number
- 1558937441
- Entity type
- Individual
- Primary specialty
- Adult Health Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- A-GNP-C
- Sex
- Female
- Sole proprietor
- No
- License
- F309522-01 (NY)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
5 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
208 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 150 | $72 |
| Continuous Monitoring of Blood Sugar Level in Tissue Fluid Using Sensor Under Skin With Interpretation and Report95251 | 39 | $26 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 19 | $103 |
Typical Medicare-allowed amounts for these services range $26–$103 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 58 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Levothyroxine Sodium | 558 | 164 |
| Semaglutidebrand: Ozempic | 252 | 60 |
| Insulin Glargine,hum.rec.anlogbrand: Lantus Solostar | 245 | 92 |
| Tirzepatidebrand: Mounjaro | 224 | 44 |
| Dulaglutidebrand: Trulicity | 215 | 60 |
| Empagliflozinbrand: Jardiance | 213 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$493 across 23 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (1)
- 34 Benwood AveBuffalo, NY 14214-1761Phone: (716) 986-9199
Registry dates
- Enumerated
- 2021-06-01
- Last updated
- 2025-08-28
- Certified
- 2025-08-28
Frequently asked questions
- What is Mary Katherine Kosowski's NPI number?
- Mary Katherine Kosowski's National Provider Identifier (NPI) is 1558937441, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Katherine Kosowski's specialty?
- Mary Katherine Kosowski is listed in the NPPES registry with a primary specialty of Adult Health Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Mary Katherine Kosowski located?
- Mary Katherine Kosowski's practice location on file with NPPES is 600 Harlem Rd, West Seneca, NY 14224-1151.
- What is Mary Katherine Kosowski's phone number?
- The practice phone number listed in the NPPES registry for Mary Katherine Kosowski is (716) 332-2121.
- Does Mary Katherine Kosowski accept Medicare?
- Mary Katherine Kosowski is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mary Katherine Kosowski's NPI active?
- Yes — Mary Katherine Kosowski's NPI (1558937441) is active in the NPPES registry as of the last update on 2025-08-28.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.