NPI Portal NPI Lookup & Verification

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

Dr. Marvin C. Mah, O.D.

Optometrist in Fremont, CA · enumerated 2005 · practices at Marvin C Mah, Od, Inc.

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

National Provider Identifier

1245228402

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Registry record

Entity type Individual (Type 1)
Name Dr. Marvin C. Mah
Credential O.D.
Sex Male
Practice address Fremont, CA, 94539
Phone (510) 438-0508
Fax (513) 661-2362
Enumeration date Oct 12, 2005
Last updated in NPPES Aug 10, 2010

Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

152W00000X Optometrist Eye and Vision Services Providers · License 006996T (CA) Primary
OD · Doctor of Optometry: A licensed optometrist providing primary vision care, eye exams, and corrective lenses. About the OD credential

Other identifiers

Identifier Type State Issuer
SD0069960T Medicaid CA -

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 is the NPI number for Marvin Mah?
The National Provider Identifier (NPI) for Marvin Mah is 1245228402, a Type 1 (individual) record in the CMS NPPES registry.
Where does Marvin Mah practice?
The practice location on file with NPPES is in Fremont, CA. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2010-08-10.