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

Dr. Nicholas Michael Mercadante, M.D.

Cardiovascular Disease Physician in Leominster, MA · enumerated 2006.

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

National Provider Identifier

1821005943

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Dr. Nicholas Michael Mercadante

Credential M.D.

Sex Male

Practice address Leominster, MA, 01453

Phone (978) 534-3179

Fax (978) 840-3161

Enumeration date Aug 2, 2006

Last updated in NPPES Sep 7, 2010

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

Taxonomy & licenses

207RC0000X Cardiovascular Disease Physician Allopathic & Osteopathic Physicians · License 48638 (MA) Primary

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

Other identifiers

Identifier	Type	State	Issuer
6191193	Medicaid	MA	-

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

Is NPI 1821005943 active?

Yes, as of the latest NPPES snapshot, NPI 1821005943 is active (record last updated 2010-09-07).

How do I verify Nicholas Mercadante's NPI record?

Cross-check NPI 1821005943 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2010-09-07.