Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Dr. Thomas M Masterson, MD

Internal Medicine Physician in Clinton, MD · enumerated 2006.

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

National Provider Identifier

1649224643

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Registry record

Entity type Individual (Type 1)

Name Dr. Thomas M Masterson

Credential MD

Sex Male

Practice address Clinton, MD, 20735

Phone (703) 356-2037

Fax (703) 734-8987

Enumeration date May 22, 2006

Last updated in NPPES Sep 30, 2017

Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 0101038350 (VA) Secondary

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License D50534 (MD) 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
0101038350	Other	VA	MEDICAL LICENSE

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

Is NPI 1649224643 active?

Yes, as of the latest NPPES snapshot, NPI 1649224643 is active (record last updated 2017-09-30).

How do I verify Thomas Masterson's NPI record?

Cross-check NPI 1649224643 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Other providers at this practice address

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Pineview Extended Care Centre, Inc. Skilled Nursing Facility · Clinton, MD NPI 1245234939 Futurecare Rehabilitation Services Inc Adult Health Nurse Practitioner · Clinton, MD NPI 1356392963 Patricia Grimes Family Nurse Practitioner · Clinton, MD NPI 1396841730 Adc 1 Inc End-Stage Renal Disease (ESRD) Treatment Clinic/Center · Clinton, MD NPI 1821339409 M Medical Group, Inc. Critical Care Medicine (Internal Medicine) Physician · Clinton, MD NPI 1780056168 California Emergency Physicians Medical Group, A Professional Corp. Internal Medicine Physician · Clinton, MD NPI 1306210554 Care Point LLC Long Term Care Hospital · Clinton, MD NPI 1073127551 Pineview Dialysis Clinic LLC End-Stage Renal Disease (ESRD) Treatment Clinic/Center · Clinton, MD NPI 1396418364

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2017-09-30.