Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Timothy Scott Mountcastle, MD

Surgery Physician in Ashburn, VA · enumerated 2006 · practices at Loudoun Medical Group, PC.

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

National Provider Identifier

1821015561

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Timothy Scott Mountcastle

Credential MD

Sex Male

Practice address 44095 Pipeline Plaza, Suite 430, Ashburn, VA, 20147

Phone (703) 858-3208

Fax (571) 291-2289

Enumeration date Jul 17, 2006

Last updated in NPPES Dec 13, 2023

Taxonomy & licenses

208200000X Plastic Surgery Physician Allopathic & Osteopathic Physicians · License 0101239935 (VA) Secondary

208600000X Surgery Physician Allopathic & Osteopathic Physicians · License 0101239935 (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
1821015561	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.

Read the full guide → Validate an NPI →

Frequently asked questions

Where does Timothy Mountcastle practice?

The practice location on file with NPPES is in Ashburn, VA. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Timothy Mountcastle?

The National Provider Identifier (NPI) for Timothy Mountcastle is 1821015561, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

Browse all →

Meredith West Physician Assistant · Ashburn, VA NPI 1225278260 Loudoun Medical Group, PC Plastic and Reconstructive Surgery Physician · Ashburn, VA NPI 1346517877

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2023-12-13.