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Dr. Mark H Greene, M.D.

Medical Oncology Physician in Rockville, MD · enumerated 2008.

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

National Provider Identifier

1801045638

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Registry record

Entity type Individual (Type 1)
Name Dr. Mark H Greene
Credential M.D.
Sex Male
Practice address 6120 Executive Blvd, Room Eps 7032, Rockville, MD, 20852
Phone (301) 594-7641
Enumeration date Sep 17, 2008
Last updated in NPPES Sep 17, 2008

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License D0022149 (MD) Secondary
207RX0202X Medical Oncology Physician Allopathic & Osteopathic Physicians · License D0022149 (MD) Primary
MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

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 Greene?
Mark Greene 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 2008-09-17.