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Dr. Mark Ewing Chisam, M.D.

Radiation Oncology Physician in Williamsburg, VA · enumerated 2006.

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

National Provider Identifier

1053381251

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Registry record

Entity type Individual (Type 1)
Name Dr. Mark Ewing Chisam
Credential M.D.
Sex Male
Practice address 3901 Treyburn Dr, Suite B, Williamsburg, VA, 23185
Phone (757) 220-4900
Fax (757) 565-5328
Enumeration date Jan 23, 2006
Last updated in NPPES Oct 3, 2013

Taxonomy & licenses

2085R0001X Radiation Oncology Physician Allopathic & Osteopathic Physicians · License 0101054200 (VA) 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
1053381251 Medicaid VA -

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 Mark Chisam?
Mark Chisam is registered in NPPES with the primary taxonomy of Radiation Oncology 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 2013-10-03.