Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

John H Oneill Jr., DO

Internal Medicine Physician in Newark, DE · enumerated 2006 · practices at Christiana Care Health System.

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

National Provider Identifier

1265445233

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Registry record

Entity type Individual (Type 1)

Name John H Oneill Jr.

Credential DO

Sex Male

Practice address 4755 Ogletown Stanton Rd Ste 5a43, Newark, DE, 19718

Phone (302) 623-0188

Enumeration date Aug 14, 2006

Last updated in NPPES Sep 24, 2018

Taxonomy & licenses

208M00000X Hospitalist Physician Allopathic & Osteopathic Physicians · License C2-0003347 (DE) Secondary

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License C20003347 (DE) 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
1689862492	Medicaid	DE	-

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

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.

What specialty is John Oneill?

John Oneill is registered in NPPES with the primary taxonomy of Internal Medicine Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2018-09-24.