Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Daniel O'Leary, M.D.

Internal Medicine Physician in Leominster, MA · enumerated 2006.

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

National Provider Identifier

1447346531

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Registry record

Entity type Individual (Type 1)

Name Daniel O'Leary

Credential M.D.

Sex Male

Practice address 50 Memorial Drive, Suite 205, Leominster, MA, 01453

Phone (978) 534-4241

Fax (978) 534-3705

Enumeration date Oct 5, 2006

Last updated in NPPES Feb 28, 2013

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 57335 (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
057334	Other	MA	TUFTS HEALTH PLAN
3031683	Medicaid	MA	-
61796	Other	MA	HARVARD PILGIRM HEALTH CA

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 Daniel O'Leary practice?

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

What is the NPI number for Daniel O'Leary?

The National Provider Identifier (NPI) for Daniel O'Leary is 1447346531, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-02-28.