Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Jeffrey Scott Mason, M.D.

Endocrinology, Diabetes & Metabolism Physician in La Verne, CA · enumerated 2006.

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

National Provider Identifier

1255308912

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Registry record

Entity type Individual (Type 1)

Name Dr. Jeffrey Scott Mason

Credential M.D.

Sex Male

Practice address 5670 Shemiran St, La Verne, CA, 91750

Phone (909) 593-4079

Fax (951) 274-3056

Enumeration date Mar 1, 2006

Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

207RE0101X Endocrinology, Diabetes & Metabolism Physician Allopathic & Osteopathic Physicians · License G32644 (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.

Read the full guide → Validate an NPI →

Frequently asked questions

What is the NPI number for Jeffrey Mason?

The National Provider Identifier (NPI) for Jeffrey Mason is 1255308912, a Type 1 (individual) record in the CMS NPPES registry.

Where does Jeffrey Mason practice?

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

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.