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Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

William Kinney Mallon Jr., MD

Emergency Medical Services (Emergency Medicine) Physician in Stony Brook, NY · enumerated 2006.

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

National Provider Identifier

1881635811

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Registry record

Entity type Individual (Type 1)
Name William Kinney Mallon Jr.
Credential MD
Sex Male
Practice address Stony Brook Medicine Dept of Emergency, Hsc, Level 4, Room 080, Stony Brook, NY, 11794
Phone (631) 444-2478
Enumeration date Jun 9, 2006
Last updated in NPPES Nov 23, 2015

Taxonomy & licenses

207PE0004X Emergency Medical Services (Emergency Medicine) Physician Allopathic & Osteopathic Physicians · License 282233 (NY) 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
00G640550 Medicaid CA -

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.

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Frequently asked questions

Is NPI 1881635811 active?
Yes, as of the latest NPPES snapshot, NPI 1881635811 is active (record last updated 2015-11-23).
How do I verify William Mallon's NPI record?
Cross-check NPI 1881635811 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2015-11-23.