Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

William Mark Allen, M.D.

Emergency Medicine Physician in Middletown, CT · enumerated 2006.

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

National Provider Identifier

1821060369

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Registry record

Entity type Individual (Type 1)

Name William Mark Allen

Credential M.D.

Sex Male

Practice address 28 Crescent St, Middletown, CT, 06457

Phone (860) 344-6394

Fax (860) 344-6748

Enumeration date Feb 7, 2006

Last updated in NPPES Jul 9, 2007

Taxonomy & licenses

207P00000X Emergency Medicine Physician Allopathic & Osteopathic Physicians · License 034661 (CT) 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.

Read the full guide → Validate an NPI →

Frequently asked questions

Where does William Allen practice?

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

What is the NPI number for William Allen?

The National Provider Identifier (NPI) for William Allen is 1821060369, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-09.