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Internal Medicine

Louisa W. Holaday, MD

Works at hospitals in New York, NY · New York

Summary

Louisa W. Holaday, MD (Internal Medicine) is listed by Medicare at 1 hospital in New York, NY. NPI 1407238256. Medicare data says the clinician accepts Medicare assignment. Source: CMS Facility Affiliation Data, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Louisa W. Holaday, 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
11Years since medical school (graduated 2015)
University Of Michigan Medical SchoolMedical school
FemaleGender (as listed)
Icahn School of Medicine at Mount SinaiGroup practice

Quick answers

Which hospitals does Louisa W. Holaday work at?
Medicare's official clinician data lists Louisa W. Holaday at 1 hospital: Mount Sinai Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
Where does Louisa W. Holaday see patients?
Medicare's clinician data lists 2 practice locations, including New York, NY. Call before your visit to confirm the address.
What is Louisa W. Holaday's specialty?
Medicare lists Internal Medicine as the primary specialty.
Does Louisa W. Holaday accept Medicare assignment?
Yes. Medicare's clinician data says Louisa W. Holaday 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 Louisa W. Holaday?
(212) 659-8551, as listed in official Medicare / NPI Registry data.
What is Louisa W. Holaday's NPI number?
1407238256. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Louisa W. Holaday works

Medicare's Facility Affiliation Data lists Louisa W. Holaday at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.

Practice locations

Addresses where Louisa W. Holaday is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Louisa W. Holaday as a member of this group (CMS data updated 2026-10-02).

  • Icahn School of Medicine at Mount Sinai2,843 clinicians in the group

Specialties

Find other Internal Medicine doctors in New York →

Other internal medicine doctors in New York

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

All internal medicine doctors in New York →

Clinician information

CredentialMD
Medical schoolUniversity Of Michigan Medical School
Graduation year2015
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1407238256
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. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
  2. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians