Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Dr. Ian Thomas Greenwalt, M.D.
Surgery Physician in Haymarket, VA · enumerated 2014.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1720405665
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Registry record
Entity type Individual (Type 1)
Name Dr. Ian Thomas Greenwalt
Credential M.D.
Sex Male
Practice address 15195 Heathcote Blvd Ste 240, Haymarket, VA, 20169
Phone (571) 284-3460
Enumeration date Mar 27, 2014
Last updated in NPPES Dec 6, 2024
Taxonomy & licenses
2086X0206X Surgical Oncology Physician Allopathic & Osteopathic Physicians · License MD047318 (DC) Secondary
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.
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 Ian Greenwalt?
Ian Greenwalt is registered in NPPES with the primary taxonomy of Surgery Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
Other providers at this practice address
Browse all →Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2024-12-06.