Medical emergency?Emergency? Call 911. Nearest emergency roomsNearest ERs

Internal Medicine

Robert J. Alexander, MD

Sees patients in Manhasset, NY · Massapequa, NY · New York

Summary

Robert J. Alexander, MD (Internal Medicine) is enrolled with Medicare at 2 practice locations in Manhasset, NY and Massapequa, NY. NPI 1912956301. Medicare data says the clinician accepts Medicare assignment. Source: CMS National Downloadable File, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Robert J. Alexander, joined by NPI number (data updated 2026-10-02). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

At a glance

Internal MedicinePrimary specialty
YesAccepts Medicare assignment
30Years since medical school (graduated 1996)
New York College Of Osteo Medicine Of New York Institute Of TechnologyMedical school
MaleGender (as listed)
Northwell Healthcare IncGroup practice

Quick answers

Where does Robert J. Alexander see patients?
Medicare's clinician data lists 2 practice locations, including Manhasset, NY and Massapequa, NY. Call before your visit to confirm the address.
What is Robert J. Alexander's specialty?
Medicare lists Internal Medicine as the primary specialty.
Does Robert J. Alexander accept Medicare assignment?
Yes. Medicare's clinician data says Robert J. Alexander 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 Robert J. Alexander?
(516) 562-0100, as listed in official Medicare / NPI Registry data.
What is Robert J. Alexander's NPI number?
1912956301. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Practice locations

Addresses where Robert J. Alexander is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Robert J. Alexander as a member of this group (CMS data updated 2026-10-02).

  • Northwell Healthcare Inc18 clinicians in the group

Specialties

Find other Internal Medicine doctors in New York →

Other internal medicine doctors in Manhasset

Clinicians with the same Medicare primary specialty in Manhasset, NY — not a recommendation.

All internal medicine doctors in Manhasset →

Clinician information

CredentialMD
Medical schoolNew York College Of Osteo Medicine Of New York Institute Of Technology
Graduation year1996
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1912956301
CorrectionsReport 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

  1. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  2. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  3. Medicare Care Compare — official Medicare tool to look up clinicians