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Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mark Nicholson Gilroy, D.O.

Pediatrics Physician in Unionville, CT · enumerated 2013 · practices at Unionville Pediatrics.

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

National Provider Identifier

1225370349

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Registry record

Entity type Individual (Type 1)
Name Mark Nicholson Gilroy
Credential D.O.
Sex Male
Practice address 101 Main St, Unionville, CT, 06085
Enumeration date Mar 27, 2013
Last updated in NPPES Dec 19, 2019

Taxonomy & licenses

208000000X Pediatrics Physician Allopathic & Osteopathic Physicians · License 55457 (CT) Primary
DO · Doctor of Osteopathic Medicine: A fully licensed physician trained in osteopathic medical schools, with the same practice rights as an MD. About the DO 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 1225370349 active?
Yes, as of the latest NPPES snapshot, NPI 1225370349 is active (record last updated 2019-12-19).
How do I verify Mark Gilroy's NPI record?
Cross-check NPI 1225370349 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 2019-12-19.