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Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Dr. Alexander Rock, DDS, MD

Dentist in Brooklyn, NY · enumerated 2007.

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

National Provider Identifier

1821136367

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Registry record

Entity type Individual (Type 1)
Name Dr. Alexander Rock
Credential DDS, MD
Sex Male
Practice address Brooklyn, NY, 11235
Phone (347) 948-9921
Enumeration date Feb 4, 2007
Last updated in NPPES Feb 24, 2015

Street address withheld — NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

390200000X Student in an Organized Health Care Education/Training Program Student, Health Care Secondary
122300000X Dentist Dental Providers · License 052813 (NY) Primary
DDS — Doctor of Dental Surgery: A licensed dentist; DDS and DMD are equivalent dental degrees. About the DDS 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.

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Frequently asked questions

Is NPI 1821136367 active?
Yes — as of the latest NPPES snapshot, NPI 1821136367 is active (record last updated 2015-02-24).
How do I verify Alexander Rock's NPI record?
Cross-check NPI 1821136367 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2015-02-24.