Quick answers
- Which hospitals does Thomas D. O Halloran work at?
- Medicare's official clinician data lists Thomas D. O Halloran at 5 hospitals: Beth Israel Deaconess Hospital - Needham, Beth Israel Deaconess Medical Center, Cambridge Health Alliance, Mount Auburn Hospital and Winchester Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Thomas D. O Halloran see patients?
- Medicare's clinician data lists 4 practice locations, including Cambridge, MA and Boston, MA. Call before your visit to confirm the address.
- What is Thomas D. O Halloran's specialty?
- Medicare lists Cardiovascular Disease (Cardiology) as the primary specialty, and also Internal Medicine.
- Does Thomas D. O Halloran accept Medicare assignment?
- Yes. Medicare's clinician data says Thomas D. O Halloran 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 Thomas D. O Halloran offer telehealth?
- Medicare's clinician data says Thomas D. O Halloran offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Thomas D. O Halloran?
- (671) 499-5005, as listed in official Medicare / NPI Registry data.
- What is Thomas D. O Halloran's NPI number?
- 1922101294. 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 D. O Halloran works
Medicare's Facility Affiliation Data lists Thomas D. O Halloran at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Beth Israel Deaconess Hospital - NeedhamNeedham, MA · Acute Care Hospital · CCN 220083
- Beth Israel Deaconess Medical CenterBoston, MA · Acute Care Hospital · CCN 220086
- Cambridge Health AllianceCambridge, MA · Acute Care Hospital · CCN 220011
- Mount Auburn HospitalCambridge, MA · Acute Care Hospital · CCN 220002
- Winchester HospitalWinchester, MA · Acute Care Hospital · CCN 220105
Practice locations
Addresses where Thomas D. O Halloran is enrolled with Medicare (CMS data updated 2026-10-02).
- 300 Mount Auburn StCambridge, MA 02138 (671) 499‑5005
- 300 Mount Auburn St, Suite 310Cambridge, MA 02138 (617) 497‑1560
- 330 Brookline AveBoston, MA 02215 (617) 754‑8612
- 330 Mount Auburn StCambridge, MA 02138 (617) 499‑5024
Group practices
Medicare enrollment lists Thomas D. O Halloran as a member of these groups (CMS data updated 2026-10-02).
- Harvard Medical Faculty Phys at Beth Israel Deaconess Med Ctr Inc1,740 clinicians in the group
- Mount Auburn Cardiology Associates Inc11 clinicians in the group
- Macro, Inc.10 clinicians in the group
Specialties
Find other Cardiovascular Disease (Cardiology) doctors in Massachusetts →
Other cardiologists in Cambridge
Clinicians with the same Medicare primary specialty in Cambridge, MA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1997 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1922101294 |
| 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