NPI Portal NPI Lookup & Verification

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

Mr. Oliver B Diaz, M.D.

Internal Medicine Physician in Bristol, CT · enumerated 2006 · practices at Chang Song Choi MD PC.

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

National Provider Identifier

1124037312

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Registry record

Entity type Individual (Type 1)
Name Mr. Oliver B Diaz
Credential M.D.
Sex Male
Practice address Bristol, CT, 06010
Phone (860) 589-5593
Fax (860) 584-0056
Enumeration date Aug 5, 2006
Last updated in NPPES Jun 9, 2020

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

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 016620 (CT) Primary
MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier Type State Issuer
010016620CT01 Other CT BLUE SHIELD
0192997 Other CT CIGNA
83286 Other CT U.S. HEALTHCARE
P464314 Other CT OXFORD
791603 Other CT CONNECTICARE
500HBX031CT01 Other CT BLUE CROSS
4342196 Other CT AETNA
0016620600 Other CT BLUE CARE FAMILY
OR1837 Other CT HEALTHNET
001166206 Medicaid CT -

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 Oliver Diaz?
The National Provider Identifier (NPI) for Oliver Diaz is 1124037312, a Type 1 (individual) record in the CMS NPPES registry.
Where does Oliver Diaz practice?
The practice location on file with NPPES is in Bristol, CT. 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 2020-06-09.