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

Ms. Nancy Lois Klein, LCSW

Clinical Social Worker in New York, NY · enumerated 2006.

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

National Provider Identifier

1639238421

Verified

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Registry record

Entity type Individual (Type 1)

Name Ms. Nancy Lois Klein

Credential LCSW

Sex Female

Practice address New York, NY, 10023

Phone (212) 721-7240

Fax (914) 722-4372

Enumeration date Dec 7, 2006

Last updated in NPPES Jul 8, 2007

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

Taxonomy & licenses

1041C0700X Clinical Social Worker Behavioral Health & Social Service Providers · License PR015476-1 (NY) Primary

LCSW · Licensed Clinical Social Worker: A social worker licensed for clinical practice including mental-health therapy. About the LCSW credential

Other identifiers

Identifier	Type	State	Issuer
01926750	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

Is NPI 1639238421 active?

Yes, as of the latest NPPES snapshot, NPI 1639238421 is active (record last updated 2007-07-08).

How do I verify Nancy Klein's NPI record?

Cross-check NPI 1639238421 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.