Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Thomas M Herndon

Hospitalist Physician in Bethesda, MD · enumerated 2012.

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

National Provider Identifier

1821355199

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Thomas M Herndon

Sex Male

Practice address 8600 Old Georgetown Rd, Medical Staff Services, Bethesda, MD, 20814

Phone (301) 896-3100

Enumeration date Apr 11, 2012

Last updated in NPPES Jul 21, 2017

Taxonomy & licenses

208M00000X Hospitalist Physician Allopathic & Osteopathic Physicians · License D54030 (MD) Primary

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License D0054030 (MD) Secondary

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 1821355199 active?

Yes, as of the latest NPPES snapshot, NPI 1821355199 is active (record last updated 2017-07-21).

How do I verify Thomas Herndon's NPI record?

Cross-check NPI 1821355199 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

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2017-07-21.