Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Dr. Jonathan David Klonsky, MD
Surgery Physician in West Islip, NY · enumerated 2008.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1619130804
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Registry record
Entity type Individual (Type 1)
Name Dr. Jonathan David Klonsky
Credential MD
Sex Male
Practice address 754 Montauk Hwy, West Islip, NY, 11795
Phone (631) 422-0909
Fax (631) 422-6660
Enumeration date Jul 8, 2008
Last updated in NPPES Jan 17, 2014
Taxonomy & licenses
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 |
|---|---|---|---|
| 9490348 | Other | - | AETNA |
| 3153792 | Other | - | UHC |
| 151TQ1 | Other | - | BCBS |
| 8223776 | Other | - | CIGNA |
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.
Frequently asked questions
What is the NPI number for Jonathan Klonsky?
The National Provider Identifier (NPI) for Jonathan Klonsky is 1619130804, a Type 1 (individual) record in the CMS NPPES registry.
Where does Jonathan Klonsky 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
Browse all →Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2014-01-17.