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

Mary B Callahan, D.O.

Cardiovascular Disease Physician in Sandwich, MA · enumerated 2005.

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

National Provider Identifier

1518968882

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Registry record

Entity type Individual (Type 1)

Name Mary B Callahan

Credential D.O.

Sex Female

Practice address Sandwich, MA, 02563

Phone (774) 413-5457

Fax (773) 413-5985

Enumeration date Aug 9, 2005

Last updated in NPPES Jun 26, 2026

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 160179 (MA) 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

Other identifiers

Identifier	Type	State	Issuer
04-00730	Other	MA	UNITED HEALTHCARE
1518968882	Other	MA	UNICARE
160179	Other	MA	MA LICENSE
J21736	Other	MA	BLUE CROSS BLUE SHIELD
3017490	Other	MA	NEIGHBORHOOD HEALTH
69586	Other	MA	HARVARD PILGRIM
1518968882	Other	MA	HEALTH NET/ TRICARE NORTH
11079014	Other	-	CAQH
1518968882	Other	MA	MEDICARE ID
000000024479	Other	MA	BMC HEALTHNET
0058769	Other	MA	CIGNA
160179	Other	MA	TUFTS
2675818	Other	MA	AETNA
3200680	Medicaid	MA	-
1518968882	Other	MA	BOSTON MEDICAL CENTER
MC0380698G	Other	MA	MA CONTROLLED SUBSTANCE

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 Mary Callahan?

The National Provider Identifier (NPI) for Mary Callahan is 1518968882, a Type 1 (individual) record in the CMS NPPES registry.

Where does Mary Callahan practice?

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

Other providers at this practice address

Browse all →

Ramon Espinosa Internal Medicine Physician · Sandwich, MA NPI 1245287838 Cardiovascular Associates of Sandwich, LLC Cardiovascular Disease Physician · Sandwich, MA NPI 1851717474 Cardiovascular Associates of Sandwich Medical Specialty Clinic/Center · Sandwich, MA NPI 1912324641

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-06-26.