Quick answers
- Which hospitals does Laurence E. Mermelstein work at?
- Medicare's official clinician data lists Laurence E. Mermelstein at 5 hospitals: Ns/Lij HS Huntington Hospital, Ns/Lij HS Southside Hospital, St Catherine of Siena Hospital, St Charles Hospital and St Francis Hospital - The Heart Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Laurence E. Mermelstein see patients?
- Medicare's clinician data lists 7 practice locations, including Roslyn, NY, Rockville Center, NY and Huntington, NY. Call before your visit to confirm the address.
- What is Laurence E. Mermelstein's specialty?
- Medicare lists Orthopedic Surgery as the primary specialty.
- Does Laurence E. Mermelstein accept Medicare assignment?
- Yes. Medicare's clinician data says Laurence E. Mermelstein 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 Laurence E. Mermelstein?
- (631) 837-2359, as listed in official Medicare / NPI Registry data.
- What is Laurence E. Mermelstein's NPI number?
- 1326062332. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Laurence E. Mermelstein works
Medicare's Facility Affiliation Data lists Laurence E. Mermelstein at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Ns/Lij HS Huntington HospitalHuntington, NY · Acute Care Hospital · CCN 330045
- Ns/Lij HS Southside HospitalBay Shore, NY · Acute Care Hospital · CCN 330043
- St Catherine of Siena HospitalSmithtown, NY · Acute Care Hospital · CCN 330401
- St Charles HospitalPort Jefferson, NY · Acute Care Hospital · CCN 330246
- St Francis Hospital - The Heart CenterRoslyn, NY · Acute Care Hospital · CCN 330182
Practice locations
Addresses where Laurence E. Mermelstein is enrolled with Medicare (CMS data updated 2026-10-02). The first 5 of 7; the Medicare profile lists all.
- 100 Port Washington BlvdRoslyn, NY 11576
- 1000 N Village AveRockville Center, NY 11570
- 270 Park AveHuntington, NY 11743
- 45 Park AveBay Shore, NY 11706 (631) 837‑2359
- 50 Route 25aSmithtown, NY 11787 (631) 862‑3000
Group practices
Medicare enrollment lists Laurence E. Mermelstein as a member of this group (CMS data updated 2026-10-02).
- CHS Physician Partners PC743 clinicians in the group
Specialties
- Orthopedic Surgeryprimary
Other orthopedic surgeons in Roslyn
Clinicians with the same Medicare primary specialty in Roslyn, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1990 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1326062332 |
| 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