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Charles P O'Brien, M.D.

Internal Medicine Physician in Sioux Falls, SD · enumerated 2005.

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

National Provider Identifier

1124023171

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Registry record

Entity type Individual (Type 1)
Name Charles P O'Brien
Credential M.D.
Sex Male
Practice address 1305 W 18th St, Sioux Falls, SD, 57105
Phone (605) 328-2929
Fax (605) 328-8429
Enumeration date Jun 16, 2005
Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 2515 (SD) 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
6000883 Medicaid SD -

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

Where does Charles O'Brien practice?
The practice location on file with NPPES is in Sioux Falls, SD. Providers can have multiple locations; NPPES lists the primary practice address.
What is the NPI number for Charles O'Brien?
The National Provider Identifier (NPI) for Charles O'Brien is 1124023171, a Type 1 (individual) record in the CMS NPPES registry.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.