Quick answers
- Which hospitals does Mark J. Brennan work at?
- Medicare's official clinician data lists Mark J. Brennan at 1 hospital: United Health Services Hospitals, Inc. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark J. Brennan see patients?
- Medicare's clinician data lists 5 practice locations, including Binghamton, NY, Norwich, NY and Johnson City, NY. Call before your visit to confirm the address.
- What is Mark J. Brennan's specialty?
- Medicare lists Vascular Surgery as the primary specialty.
- Does Mark J. Brennan accept Medicare assignment?
- Yes. Medicare's clinician data says Mark J. Brennan 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 J. Brennan?
- (607) 337-4111, as listed in official Medicare / NPI Registry data.
- What is Mark J. Brennan's NPI number?
- 1174523443. 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 J. Brennan works
Medicare's Facility Affiliation Data lists Mark J. Brennan at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- United Health Services Hospitals, IncBinghamton, NY · Acute Care Hospital · CCN 330394
Practice locations
Addresses where Mark J. Brennan is enrolled with Medicare (CMS data updated 2026-10-02).
- 10 -24 Mitchell AveBinghamton, NY 13903
- 179 N Broad St, UHS Senior Living NorwichNorwich, NY 13815 (607) 337‑4111
- 30 Harrison StJohnson City, NY 13790 (607) 763‑8101
- 33 -57 Harrison StJohnson City, NY 13790 (607) 763‑6101
- 54 Main StCandor, NY 13743 (607) 659‑7272
Group practices
Medicare enrollment lists Mark J. Brennan as a member of these groups (CMS data updated 2026-10-02).
- United Health Services Hospitals, Inc.477 clinicians in the group
- Chenango Memorial Hospital Inc111 clinicians in the group
Specialties
- Vascular Surgeryprimary
Other vascular surgeons in New York
Clinicians with the same Medicare primary specialty in New York — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | Philadelphia College Of Osteopathic Medicine |
| Graduation year | 1994 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1174523443 |
| 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