Quick answers
- Which hospitals does Mark Gelfand work at?
- Medicare's official clinician data lists Mark Gelfand at 2 hospitals: Maimonides Medical Center and NYU Langone Hospitals. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark Gelfand see patients?
- Medicare's clinician data lists 2 practice locations, including Brooklyn, NY. Call before your visit to confirm the address.
- What is Mark Gelfand's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Mark Gelfand accept Medicare assignment?
- Yes. Medicare's clinician data says Mark Gelfand 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 Mark Gelfand offer telehealth?
- Medicare's clinician data says Mark Gelfand offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Mark Gelfand?
- (718) 934-4842, as listed in official Medicare / NPI Registry data.
- What is Mark Gelfand's NPI number?
- 1801849658. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Mark Gelfand works
Medicare's Facility Affiliation Data lists Mark Gelfand at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Maimonides Medical CenterBrooklyn, NY · Acute Care Hospital · CCN 330194
- NYU Langone HospitalsNew York, NY · Acute Care Hospital · CCN 330214
Practice locations
Addresses where Mark Gelfand is enrolled with Medicare (CMS data updated 2026-10-02).
- 415 Ocean View AveBrooklyn, NY 11235 (718) 934‑4842
- 415 Oceanview Ave, Ground FloorBrooklyn, NY 11235
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Brooklyn
Clinicians with the same Medicare primary specialty in Brooklyn, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1986 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1801849658 |
| 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