Quick answers
- Which hospitals does Mark S. St Marie work at?
- Medicare's official clinician data lists Mark S. St Marie at 1 hospital: Mercy Hospital of Buffalo. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark S. St Marie see patients?
- Medicare's clinician data lists 1 practice location in Williamsville, NY. Call before your visit to confirm the address.
- What is Mark S. St Marie's specialty?
- Medicare lists Gastroenterology as the primary specialty, and also Internal Medicine.
- Does Mark S. St Marie accept Medicare assignment?
- Yes. Medicare's clinician data says Mark S. St Marie 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.
- Does Mark S. St Marie offer telehealth?
- Medicare's clinician data says Mark S. St Marie offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Mark S. St Marie?
- (716) 204-4532, as listed in official Medicare / NPI Registry data.
- What is Mark S. St Marie's NPI number?
- 1629150792. 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 S. St Marie works
Medicare's Facility Affiliation Data lists Mark S. St Marie at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Mercy Hospital of BuffaloBuffalo, NY · Acute Care Hospital · CCN 330279
Practice locations
Addresses where Mark S. St Marie is enrolled with Medicare (CMS data updated 2026-10-02).
- 111 N Maplemere Rd, Suite 200Williamsville, NY 14221 (716) 204‑4532
Group practices
Medicare enrollment lists Mark S. St Marie as a member of this group (CMS data updated 2026-10-02).
- General Physician PC501 clinicians in the group
Specialties
- Gastroenterologyprimary
- Internal Medicinealso
Other gastroenterologists in Williamsville
Clinicians with the same Medicare primary specialty in Williamsville, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1976 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1629150792 |
| 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