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

Dr. Apostolos John Giannas, O.D.

Optometrist in Baltimore, MD · enumerated 2007.

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

National Provider Identifier

1790906378

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Registry record

Entity type Individual (Type 1)
Name Dr. Apostolos John Giannas
Credential O.D.
Sex Male
Practice address Baltimore, MD, 21237
Phone (410) 866-2022
Fax (410) 866-2031
Enumeration date May 1, 2007
Last updated in NPPES Jun 20, 2016

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 TA0814 (MD) Primary
152WC0802X Corneal and Contact Management Optometrist Eye and Vision Services Providers · License TA0814 (MD) Secondary
OD · Doctor of Optometry: A licensed optometrist providing primary vision care, eye exams, and corrective lenses. About the OD 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

What is the NPI number for Apostolos Giannas?
The National Provider Identifier (NPI) for Apostolos Giannas is 1790906378, a Type 1 (individual) record in the CMS NPPES registry.
Where does Apostolos Giannas practice?
The practice location on file with NPPES is in Baltimore, MD. Providers can have multiple locations; NPPES lists the primary practice address.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2016-06-20.