Quick answers
- Which hospitals does Mark Sieminski work at?
- Medicare's official clinician data lists Mark Sieminski at 1 hospital: Kaleida Health. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark Sieminski see patients?
- Medicare's clinician data lists 1 practice location in Buffalo, NY. Call before your visit to confirm the address.
- What is Mark Sieminski's specialty?
- Medicare lists Emergency Medicine as the primary specialty.
- Does Mark Sieminski accept Medicare assignment?
- Yes. Medicare's clinician data says Mark Sieminski 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 Mark Sieminski?
- (716) 898-3478, as listed in official Medicare / NPI Registry data.
- What is Mark Sieminski's NPI number?
- 1003057779. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Mark Sieminski works
Medicare's Facility Affiliation Data lists Mark Sieminski 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
Practice locations
Addresses where Mark Sieminski is enrolled with Medicare (CMS data updated 2026-10-02).
- 462 Grider StBuffalo, NY 14215 (716) 898‑3478
Group practices
Medicare enrollment lists Mark Sieminski as a member of this group (CMS data updated 2026-10-02).
- University Emergency Medical Services Inc.95 clinicians in the group
Specialties
- Emergency Medicineprimary
Other emergency medicine doctors in Buffalo
Clinicians with the same Medicare primary specialty in Buffalo, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Virginia School Of Medicine |
| Graduation year | 2005 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1003057779 |
| 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