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

Ronald Ira Lenefsky, MD

Infectious Disease Physician in West Islip, NY · enumerated 2005.

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

National Provider Identifier

1588663546

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Registry record

Entity type Individual (Type 1)

Name Ronald Ira Lenefsky

Credential MD

Sex Male

Practice address West Islip, NY, 11795

Phone (631) 587-7733

Fax (631) 587-7798

Enumeration date Jul 20, 2005

Last updated in NPPES Dec 30, 2024

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 191235 (NY) Secondary

207RI0200X Infectious Disease Physician Allopathic & Osteopathic Physicians · License 191235 (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
01816540	Medicaid	NY	-

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

What is the NPI number for Ronald Lenefsky?

The National Provider Identifier (NPI) for Ronald Lenefsky is 1588663546, a Type 1 (individual) record in the CMS NPPES registry.

Where does Ronald Lenefsky practice?

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

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2024-12-30.