Quick answers
- Which hospitals does Marc S. Greenstein work at?
- Medicare's official clinician data lists Marc S. Greenstein at 1 hospital: Strong Memorial Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Marc S. Greenstein see patients?
- Medicare's clinician data lists 2 practice locations, including Webster, NY and Rochester, NY. Call before your visit to confirm the address.
- What is Marc S. Greenstein's specialty?
- Medicare lists Obstetrics/Gynecology as the primary specialty.
- Does Marc S. Greenstein accept Medicare assignment?
- Yes. Medicare's clinician data says Marc S. Greenstein 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 Marc S. Greenstein?
- (585) 671-6790, as listed in official Medicare / NPI Registry data.
- What is Marc S. Greenstein's NPI number?
- 1346354404. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Marc S. Greenstein works
Medicare's Facility Affiliation Data lists Marc S. Greenstein at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Strong Memorial HospitalRochester, NY · Acute Care Hospital · CCN 330285
Practice locations
Addresses where Marc S. Greenstein is enrolled with Medicare (CMS data updated 2026-10-02).
- 1682 Empire BlvdWebster, NY 14580 (585) 671‑6790
- 3101 W Ridge Rd, Bldg DRochester, NY 14626 (585) 225‑1580
Group practices
Medicare enrollment lists Marc S. Greenstein as a member of this group (CMS data updated 2026-10-02).
- University of Rochester Obgyn Subspecialties17 clinicians in the group
Specialties
- Obstetrics/Gynecologyprimary
Other OB-GYNs in Webster
Clinicians with the same Medicare primary specialty in Webster, NY — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | New York College Of Osteo Medicine Of New York Institute Of Technology |
| Graduation year | 1991 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1346354404 |
| 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