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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

DR. WILLIAM M. MCCORMACK M.D.
NPI 1366436008
Internal Medicine - Infectious Disease in Brooklyn, NY

Active since September 08, 2005
450 CLARKSON AVE, SUITE A, BROOKLYN, NY 11203(718) 270-1432(718) 270-4123 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 09, 2026.

About Dr. William M. Mccormack M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. WILLIAM M. MCCORMACK M.D. (NPI 1366436008) is an individual infectious disease provider in Brooklyn, New York, licensed in New York (092245-1) and active in the NPI registry since September 2005.

NPPES Registry Identity

NPI1366436008
Entity TypeIndividualMale
Primary Taxonomy207RI0200X
Provider Legal NameDR. WILLIAM M. MCCORMACKCredential: M.D.
Location Address450 CLARKSON AVE, SUITE ABrooklyn, NY 11203-2056
Mailing Address450 Clarkson Ave, Box 1262Brooklyn, NY 11203-2056 · (718) 270-8867 · Fax (718) 270-1794
Phone(718) 270-1432
Fax(718) 270-4123
Sole ProprietorNo
Enumeration DateSeptember 8, 2005
Last NPPES UpdateJuly 13, 2026
✔ NPI 1366436008 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Infectious DiseaseAllopathic & Osteopathic Physicians
Taxonomy Code207RI0200X
License✔ Licensed in NY · 092245-1
Definition
An internist who deals with infectious diseases of all types and in all organ systems. Conditions requiring selective use of antibiotics call for this special skill. This physician often diagnoses and treats AIDS patients and patients with fevers which have not been explained. Infectious disease specialists may also have expertise in preventive medicine and travel medicine.
450 CLARKSON AVE, Brooklyn, NY 11203
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Other Identifiers 1

Medicaid00696699NY

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

SUNY DOWNSTATE MEDICAL CENTER UHB
Obstetrics & Gynecology
450 CLARKSON AVE
BROOKLYN, NY 11203
Kings County (718) 363-2908
UNIVERSITY PHYSICIANS OF BROOKLYN
Internal Medicine (Gastroenterology)
450 CLARKSON AVE, SUITE A
BROOKLYN, NY 11203
Kings County (718) 270-1112
SNEHALATA R TOPGI MD
Emergency Medicine
450 CLARKSON AVE
BROOKLYN, NY 11203
Kings County (718) 270-3295
DR. MARYAM NOORI KOLOORI M.D.
Student in an Organized Health Care Education/Training Program
450 CLARKSON AVE, SUNY DOWNSTATE MEDICAL CENTER
BROOKLYN, NY 11203
Kings County (412) 737-3789
DR. VIVEK YADAV MD
Internal Medicine (Pulmonary Disease)
450 CLARKSON AVE
BROOKLYN, NY 11203
Kings County (718) 270-3302
DR. DANIEL BEEGAN MD
Family Medicine
450 CLARKSON AVE, MSC 67
BROOKLYN, NY 11203
Kings County (718) 270-4096
ELIEZER LEVITANSKY DO
Emergency Medicine
450 CLARKSON AVE
BROOKLYN, NY 11203
Kings County (245) 331-8718
MIGUEL ANGEL BARRIOS MD
Emergency Medicine
450 CLARKSON AVE
BROOKLYN, NY 11203
Kings County (718) 245-4798

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is William Mccormack's NPI number?

The NPI number for William Mccormack is 1366436008. It was assigned to this individual provider in the NPPES registry on September 8, 2005.

Where is William Mccormack located?

William Mccormack practices at 450 Clarkson Ave Suite A, Brooklyn, NY 11203. The listed phone number is (718) 270-1432.

What is William Mccormack's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Infectious Disease, with taxonomy code 207RI0200X.

When was this NPI record last updated?

The NPPES record for William Mccormack was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 35 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.