Quick answers
- Which hospitals does Thomas J. O Brien work at?
- Medicare's official clinician data lists Thomas J. O Brien at 1 hospital: Peconic Bay Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Thomas J. O Brien see patients?
- Medicare's clinician data lists 1 practice location in Riverhead, NY. Call before your visit to confirm the address.
- What is Thomas J. O Brien's specialty?
- Medicare lists Physician Assistant as the primary specialty.
- Does Thomas J. O Brien accept Medicare assignment?
- Yes. Medicare's clinician data says Thomas J. 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 Thomas J. O Brien?
- (631) 548-6101, as listed in official Medicare / NPI Registry data.
- What is Thomas J. O Brien's NPI number?
- 1659636454. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Thomas J. O Brien works
Medicare's Facility Affiliation Data lists Thomas J. O Brien at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Peconic Bay Medical CenterRiverhead, NY · Acute Care Hospital · CCN 330107
Practice locations
Addresses where Thomas J. O Brien is enrolled with Medicare (CMS data updated 2026-10-02).
- 1 Heroes WayRiverhead, NY 11901 (631) 548‑6101
Group practices
Medicare enrollment lists Thomas J. O Brien as a member of this group (CMS data updated 2026-10-02).
- Central Suffolk Hospital95 clinicians in the group
Specialties
- Physician Assistantprimary
Other physician assistants in Riverhead
Clinicians with the same Medicare primary specialty in Riverhead, NY — not a recommendation.
Clinician information
| Graduation year | 2012 |
|---|---|
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1659636454 |
| 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