Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Irvin Robert Horowitz, MD

Dermatology Physician in Rockville, MD · enumerated 2006 · practices at Rockville Pediatric Dental LLC.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1376647537

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Registry record

Entity type Individual (Type 1)

Name Irvin Robert Horowitz

Credential MD

Sex Male

Practice address 121 Congressional Lane, Suite 416, Rockville, MD, 20852

Phone (301) 468-9090

Fax (301) 468-1420

Enumeration date Sep 11, 2006

Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

207N00000X Dermatology Physician Allopathic & Osteopathic Physicians · License D0015098 (MD) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

Where does Irvin Horowitz practice?

The practice location on file with NPPES is in Rockville, MD. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Irvin Horowitz?

The National Provider Identifier (NPI) for Irvin Horowitz is 1376647537, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

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Hsuan Huang Pediatrics Physician · Rockville, MD NPI 1083723704 Rockville Pediatric Dental LLC Pediatric Dentistry · Rockville, MD NPI 1497994461

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.