Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Robert Lionel Jack, M.D.

Specialist in Menlo Park, CA · enumerated 2006.

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

National Provider Identifier

1376601443

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Registry record

Entity type Individual (Type 1)

Name Robert Lionel Jack

Credential M.D.

Sex Male

Practice address 1225 Crane St, Menlo Park, CA, 94025

Phone (650) 323-0231

Fax (650) 565-8297

Enumeration date Dec 4, 2006

Last updated in NPPES Jan 3, 2012

Taxonomy & licenses

174400000X Specialist Other Service Providers · License G17236 (CA) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD 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 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 Robert Jack?

Robert Jack is registered in NPPES with the primary taxonomy of Specialist. 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 2012-01-03.