Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Marshall Lawrence Horwitz, D.D.S.

Dentist in Worcester, MA · enumerated 2005.

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

National Provider Identifier

1750374468

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Registry record

Entity type Individual (Type 1)

Name Dr. Marshall Lawrence Horwitz

Credential D.D.S.

Sex Male

Practice address 111 Elm St, Suite 101, Worcester, MA, 01609

Phone (508) 799-4626

Fax (508) 791-4288

Enumeration date Aug 27, 2005

Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

122300000X Dentist Dental Providers · License 13920 (MA) 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.

Read the full guide → Validate an NPI →

Frequently asked questions

What is the NPI number for Marshall Horwitz?

The National Provider Identifier (NPI) for Marshall Horwitz is 1750374468, a Type 1 (individual) record in the CMS NPPES registry.

Where does Marshall Horwitz practice?

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

Other providers at this practice address

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