Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Ralph J Blair, M.D.

Hospitalist Physician in Cambridge, MA · enumerated 2006.

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

National Provider Identifier

1275568230

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Registry record

Entity type Individual (Type 1)

Name Ralph J Blair

Credential M.D.

Sex Male

Practice address 330 Mount Auburn St, Cambridge, MA, 02138

Phone (617) 492-3500

Enumeration date Jul 11, 2006

Last updated in NPPES Sep 11, 2025

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 51227 (MA) Secondary

207RI0200X Infectious Disease Physician Allopathic & Osteopathic Physicians · License 51227 (MA) Secondary

208M00000X Hospitalist Physician Allopathic & Osteopathic Physicians · License 51227 (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
3004481	Medicaid	MA	-
722575	Other	MA	TUFTS
0015282	Other	MA	NEIGHBORHOOD HEALTH
J05173	Other	MA	BLUE CROSS
PV408	Other	MA	HARVARD PILGRIM

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

What specialty is Ralph Blair?

Ralph Blair is registered in NPPES with the primary taxonomy of Hospitalist Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-09-11.