Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Brian O'Connor, MD

Medical Oncology Physician in Frederick, MD · enumerated 2005.

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

National Provider Identifier

1174515050

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Registry record

Entity type Individual (Type 1)

Name Dr. Brian O'Connor

Credential MD

Sex Male

Practice address 1562 Opossumtown Pike, Frederick, MD, 21702

Phone (301) 662-8477

Enumeration date Aug 17, 2005

Last updated in NPPES May 15, 2019

Taxonomy & licenses

207RH0003X Hematology & Oncology Physician Allopathic & Osteopathic Physicians · License D0031761 (MD) Secondary

207RX0202X Medical Oncology Physician Allopathic & Osteopathic Physicians · License D31761 (MD) 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
28658979	Other	-	AETNA PVN
W575-0002	Other	-	CAREFIRST BCBS GHMSI
523014-01	Other	-	CAREFIRST BCBS MARYLAND
81961100	Medicaid	MD	-
971641	Other	-	UNITED

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 Brian O'Connor?

Brian O'Connor is registered in NPPES with the primary taxonomy of Medical Oncology Physician. 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.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2019-05-15.