Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. David M Callahan, PH.D.

Psychologist in Sandwich, MA · enumerated 2006.

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

National Provider Identifier

1205865797

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Registry record

Entity type Individual (Type 1)

Name Dr. David M Callahan

Credential PH.D.

Sex Male

Practice address 449 Route 130, Suite 12, Sandwich, MA, 02563

Phone (508) 888-7744

Fax (508) 888-7725

Enumeration date Jun 30, 2006

Last updated in NPPES Jan 30, 2013

Taxonomy & licenses

103T00000X Psychologist Behavioral Health & Social Service Providers · License 4061 (MA) Primary

PHD · Doctor of Philosophy: A doctoral degree; in healthcare often held by clinical psychologists and researchers. About the PHD credential

Other identifiers

Identifier	Type	State	Issuer
0516821	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.

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Frequently asked questions

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

What specialty is David Callahan?

David Callahan is registered in NPPES with the primary taxonomy of Psychologist. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-01-30.