Quick answers
- Which hospitals does Brian M. Karaszewski work at?
- Medicare's official clinician data lists Brian M. Karaszewski at 4 hospitals: Kaleida Health, Kenmore Mercy Hospital, Mount St. Mary's Hospital & Health Center and Sisters of Charity Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Brian M. Karaszewski see patients?
- Medicare's clinician data lists 1 practice location in Williamsville, NY. Call before your visit to confirm the address.
- What is Brian M. Karaszewski's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Brian M. Karaszewski accept Medicare assignment?
- Yes. Medicare's clinician data says Brian M. Karaszewski accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Brian M. Karaszewski?
- (716) 631-3555, as listed in official Medicare / NPI Registry data.
- What is Brian M. Karaszewski's NPI number?
- 1255478376. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Brian M. Karaszewski works
Medicare's Facility Affiliation Data lists Brian M. Karaszewski at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Kaleida HealthBuffalo, NY · Acute Care Hospital · CCN 330005
- Kenmore Mercy HospitalKenmore, NY · Acute Care Hospital · CCN 330102
- Mount St. Mary's Hospital & Health CenterLewiston, NY · Acute Care Hospital · CCN 330188
- Sisters of Charity HospitalBuffalo, NY · Acute Care Hospital · CCN 330078
Practice locations
Addresses where Brian M. Karaszewski is enrolled with Medicare (CMS data updated 2026-10-02).
- 400 International DrWilliamsville, NY 14221 (716) 631‑3555
Group practices
Medicare enrollment lists Brian M. Karaszewski as a member of this group (CMS data updated 2026-10-02).
- Brain and Spine Medical Services PLLC56 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Williamsville
Clinicians with the same Medicare primary specialty in Williamsville, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | State University Of New York At Buffalo School Of Medicine |
| Graduation year | 1997 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1255478376 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians