Quick answers
- Which hospitals does John Mahon work at?
- Medicare's official clinician data lists John Mahon at 5 hospitals: Lenox Hill Hospital, Long Island Jewish Medical Center, North Shore University Hospital, Northern Westchester Hospital and Phelps Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John Mahon see patients?
- Medicare's clinician data lists 3 practice locations, including New York, NY, Manhasset, NY and Rego Park, NY. Call before your visit to confirm the address.
- What is John Mahon's specialty?
- Medicare lists Diagnostic Radiology as the primary specialty.
- Does John Mahon accept Medicare assignment?
- Yes. Medicare's clinician data says John Mahon 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 Mahon?
- (212) 744-5538, as listed in official Medicare / NPI Registry data.
- What is John Mahon's NPI number?
- 1326509373. 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 Mahon works
Medicare's Facility Affiliation Data lists John Mahon at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Lenox Hill HospitalNew York, NY · Acute Care Hospital · CCN 330119
- Long Island Jewish Medical CenterNew Hyde Park, NY · Acute Care Hospital · CCN 330195
- North Shore University HospitalManhasset, NY · Acute Care Hospital · CCN 330106
- Northern Westchester HospitalMount Kisco, NY · Acute Care Hospital · CCN 330162
- Phelps HospitalSleepy Hollow, NY · Acute Care Hospital · CCN 330261
Practice locations
Addresses where John Mahon is enrolled with Medicare (CMS data updated 2026-10-02).
- 1421 3rd AveNew York, NY 10028 (212) 744‑5538
- 300 Community DrManhasset, NY 11030 (516) 876‑5555
- 9525 Queens BlvdRego Park, NY 11374 (718) 360‑5522
Group practices
Medicare enrollment lists John Mahon as a member of these groups (CMS data updated 2026-10-02).
- North Shore-Lij Medical PC6,440 clinicians in the group
- Southside Faculty Medical Affiliates University Faculty Practice Corp231 clinicians in the group
Specialties
- Diagnostic Radiologyprimary
Other radiologists in New York
Clinicians with the same Medicare primary specialty in New York, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | State University Of New York At Stony Brook, School Of Medicine |
| Graduation year | 2019 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1326509373 |
| 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