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

Dr. John Louis Ryan, M.D.

Infectious Disease Physician in New York, NY · enumerated 2006 · practices at Kadmon Corporation, LLC.

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

National Provider Identifier

1821046095

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Registry record

Entity type Individual (Type 1)

Name Dr. John Louis Ryan

Credential M.D.

Sex Male

Practice address New York, NY, 10016

Phone (212) 308-6000

Enumeration date May 4, 2006

Last updated in NPPES Jul 22, 2014

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

Taxonomy & licenses

207RI0200X Infectious Disease Physician Allopathic & Osteopathic Physicians · License 82080 (MA) Secondary

207RI0200X Infectious Disease Physician Allopathic & Osteopathic Physicians · License 268115 (NY) 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.

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Frequently asked questions

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

What specialty is John Ryan?

John Ryan is registered in NPPES with the primary taxonomy of Infectious Disease Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Other providers at this practice address

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Kadmon Corporation, LLC Clinical Medical Laboratory · New York, NY NPI 1306253331

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2014-07-22.