Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mark O Duncan, DO

Neurological Surgery Physician in Lawton, OK · enumerated 2005 · practices at Osu Center for Health Sciences.

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

National Provider Identifier

1538155122

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Registry record

Entity type Individual (Type 1)

Name Mark O Duncan

Credential DO

Sex Male

Practice address 110 Nw 31st St Fl 2, Lawton, OK, 73505

Phone (580) 248-5255

Fax (580) 248-2036

Enumeration date Sep 20, 2005

Last updated in NPPES Jul 10, 2013

Taxonomy & licenses

207T00000X Neurological Surgery Physician Allopathic & Osteopathic Physicians · License 3848 (OK) 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
100114100A	Medicaid	OK	-
140007550	Other	-	RAILROAD MEDICARE
7358213	Other	OK	AETNA
175194701	Other	OK	DOL

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 specialty is Mark Duncan?

Mark Duncan is registered in NPPES with the primary taxonomy of Neurological Surgery 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.

Other providers at this practice address

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Brett Barnes Sports Medicine (Orthopaedic Surgery) Physician · Lawton, OK NPI 1326049719 Scott Kochenower Foot & Ankle Surgery Podiatrist · Lawton, OK NPI 1174848790 Kody King Orthopaedic Surgery Physician · Lawton, OK NPI 1194037713 Nancy Varkey Physician Assistant · Lawton, OK NPI 1326387739 Osu Center for Health Sciences Clinic/Center · Lawton, OK NPI 1730742693 Tracy Sweeney Surgical Assistant · Lawton, OK NPI 1942020334 Sydney Aust Surgical Assistant · Lawton, OK NPI 1437077971

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-07-10.