Quick answers
- Does Gregory J. Gagnon accept Medicare assignment?
- Yes. Medicare's clinician data says Gregory J. Gagnon accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- What is Gregory J. Gagnon's NPI number?
- 1710640479. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Gregory J. Gagnon works
Medicare's Facility Affiliation Data lists Gregory J. Gagnon at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Mount Sinai Beth IsraelNew York, NY · Acute Care Hospital · closed, according to its website · CCN 330169
Practice locations
Addresses where Gregory J. Gagnon is enrolled with Medicare (CMS data updated October 2, 2026).
- 1425 Madison AveNew York, NY 10029 (212) 824‑8150
Group practices
Medicare enrollment lists Gregory J. Gagnon as a member of this group (CMS data updated October 2, 2026).
- Icahn School of Medicine at Mount Sinai2,843 clinicians in the group
Specialties
- Clinical Psychologistprimary
Other clinical psychologists in New York
Clinicians with the same Medicare primary specialty in New York, NY — not a recommendation.
Other clinicians in Icahn School of Medicine at Mount Sinai
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Graduation year | 2020 |
|---|---|
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1710640479 |
| 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 October 2, 2026, retrieved October 29, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- 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