Quick answers
- Which hospitals does Nathan O'Brien work at?
- Medicare's official clinician data lists Nathan O'Brien at 2 hospitals: Erie County Medical Center and Kaleida Health. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Nathan O'Brien see patients?
- Medicare's clinician data lists 2 practice locations, including Buffalo, NY. Call before your visit to confirm the address.
- What is Nathan O'Brien's specialty?
- Medicare lists Emergency Medicine as the primary specialty.
- Does Nathan O'Brien accept Medicare assignment?
- Yes. Medicare's clinician data says Nathan O'Brien 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 Nathan O'Brien?
- (716) 691-8838, as listed in official Medicare / NPI Registry data.
- What is Nathan O'Brien's NPI number?
- 1407438450. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Nathan O'Brien works
Medicare's Facility Affiliation Data lists Nathan O'Brien at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Erie County Medical CenterBuffalo, NY · Acute Care Hospital · CCN 330219
- Kaleida HealthBuffalo, NY · Acute Care Hospital · CCN 330005
Practice locations
Addresses where Nathan O'Brien is enrolled with Medicare (CMS data updated 2026-10-02).
- 100 High StBuffalo, NY 14203 (716) 691‑8838
- 462 Grider StBuffalo, NY 14215 (716) 898‑3478
Group practices
Medicare enrollment lists Nathan O'Brien 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
| Medical school | Drexel University College Of Medicine |
|---|---|
| Graduation year | 2021 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1407438450 |
| 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