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MARK D. HOROWITZ MD PC
NPI 1780988717
Internal Medicine - Rheumatology in New York, NY

Active since January 05, 2011
21 E 90TH ST, NEW YORK, NY 10128(212) 860-3077(212) 410-7410 Get Directions Write a Review

NPPES record last updated: January 5, 2011. Verified against the NPPES registry weekly; last sync: November 01, 2026.

About Mark D. Horowitz Md Pc NPPES

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

MARK D. HOROWITZ MD PC (NPI 1780988717) is a healthcare organization registered as a rheumatology in New York, New York and active in the NPI registry since January 2011. The organization lists Mark D Horowitz, President, as its authorized official.

NPPES Registry Identity

NPI1780988717
Entity TypeOrganization
Primary Taxonomy207RR0500X
Legal Business NameMARK D. HOROWITZ MD PC
Location Address21 E 90TH STNew York, NY 10128-0654
Mailing Address21 E 90th StNew York, NY 10128-0654 · (212) 860-3077 · Fax (212) 410-7410
Phone(212) 860-3077
Fax(212) 410-7410
Organization SubpartNo
Authorized OfficialMark D HorowitzPresident · (212) 860-3077
Enumeration DateJanuary 5, 2011
✔ NPI 1780988717 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · RheumatologyAllopathic & Osteopathic Physicians
Taxonomy Code207RR0500X
Definition
An internist who treats diseases of joints, muscle, bones and tendons. This specialist diagnoses and treats arthritis, back pain, muscle strains, common athletic injuries and collagen diseases.
21 E 90TH ST, New York, NY 10128
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Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Mark D. Horowitz Md Pc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 1 clinician reassigns Medicare billing to Mark D. Horowitz MD PC, which bills Medicare for the services this clinician delivers.

Clinician (1)

Mark Horowitz, MD
Internal Medicine
NPI 1154490530
21 EAST 90TH ST
New York, NY 10128
(212) 860-3077
✔ PECOS✔ Accepts MedicareSame address

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

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 Mark D. Horowitz MD PC's NPI number?

The NPI number for Mark D. Horowitz MD PC is 1780988717. It was assigned to this organization in the NPPES registry on January 5, 2011.

Where is Mark D. Horowitz MD PC located?

Mark D. Horowitz MD PC is located at 21 E 90th St, New York, NY 10128. The listed phone number is (212) 860-3077.

What is Mark D. Horowitz MD PC's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Rheumatology, with taxonomy code 207RR0500X.

Is Mark D. Horowitz MD PC enrolled in Medicare?

Yes. Mark D. Horowitz MD PC is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Mark D. Horowitz MD PC?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Internal Medicine) reassigns their Medicare billing to Mark D. Horowitz MD PC. A reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for the clinician's services. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Mark D. Horowitz MD PC was last updated on January 5, 2011. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 years 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.