Quick answers
- Which hospitals does John Ahern work at?
- Medicare's official clinician data lists John Ahern at 1 hospital: Cambridge Health Alliance. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John Ahern see patients?
- Medicare's clinician data lists 2 practice locations, including Cambridge, MA. Call before your visit to confirm the address.
- What is John Ahern's specialty?
- Medicare lists Family Practice as the primary specialty.
- Does John Ahern accept Medicare assignment?
- Yes. Medicare's clinician data says John Ahern 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 John Ahern?
- (617) 665-3000, as listed in official Medicare / NPI Registry data.
- What is John Ahern's NPI number?
- 1699397141. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where John Ahern works
Medicare's Facility Affiliation Data lists John Ahern at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Cambridge Health AllianceCambridge, MA · Acute Care Hospital · CCN 220011
Practice locations
Addresses where John Ahern is enrolled with Medicare (CMS data updated 2026-10-02).
- 163 Gore StCambridge, MA 02141 (617) 665‑3000
- 75 Mount Auburn StCambridge, MA 02138 (617) 496‑8700
Group practices
Medicare enrollment lists John Ahern as a member of these groups (CMS data updated 2026-10-02).
- Cambridge Public Health Commission656 clinicians in the group
- President and Fellows of Harvard College97 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Cambridge
Clinicians with the same Medicare primary specialty in Cambridge, MA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2015 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1699397141 |
| 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