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

Dr. Frank Paul Castaldi, DO

Optometrist in Stamford, CT · enumerated 2006.

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

National Provider Identifier

1043396302

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Registry record

Entity type Individual (Type 1)

Name Dr. Frank Paul Castaldi

Credential DO

Sex Male

Practice address Stamford, CT, 06901

Phone (203) 324-1606

Fax (203) 324-4357

Enumeration date Oct 30, 2006

Last updated in NPPES Sep 27, 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 1074 (CT) Primary

DO · Doctor of Osteopathic Medicine: A fully licensed physician trained in osteopathic medical schools, with the same practice rights as an MD. About the DO credential

Other identifiers

Identifier	Type	State	Issuer
090001074CT01	Other	CT	ANTHEM
004068409	Medicaid	CT	-
7359876831	Other	CT	CONNECTICARE

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 specialty is Frank Castaldi?

Frank Castaldi is registered in NPPES with the primary taxonomy of Optometrist. 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.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2010-09-27.