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Leonard M Klein

Hematology & Oncology Physician in Niles, IL · enumerated 2005.

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

National Provider Identifier

1255328878

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Registry record

Entity type Individual (Type 1)
Name Leonard M Klein
Sex Male
Practice address 8915 W Golf Rd, Niles, IL, 60714
Phone (847) 827-9060
Fax (847) 827-7196
Enumeration date Sep 29, 2005
Last updated in NPPES Dec 17, 2021

Taxonomy & licenses

207RH0003X Hematology & Oncology Physician Allopathic & Osteopathic Physicians · License 036064246 (IL) Primary

Other identifiers

Identifier Type State Issuer
036064246 Medicaid IL -

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

What specialty is Leonard Klein?
Leonard Klein is registered in NPPES with the primary taxonomy of Hematology & Oncology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
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.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2021-12-17.