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

Dr. Diane R Koslow, PH.D.

Psychologist in Rockville, MD · enumerated 2007.

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

National Provider Identifier

1851500391

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Registry record

Entity type Individual (Type 1)
Name Dr. Diane R Koslow
Credential PH.D.
Sex Female
Practice address Rockville, MD, 20852
Phone (301) 770-2847
Enumeration date May 22, 2007
Last updated in NPPES Jul 11, 2007

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

Taxonomy & licenses

103T00000X Psychologist Behavioral Health & Social Service Providers · License 02135 (MD) Primary
PHD · Doctor of Philosophy: A doctoral degree; in healthcare often held by clinical psychologists and researchers. About the PHD 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 NPI 1851500391 active?
Yes, as of the latest NPPES snapshot, NPI 1851500391 is active (record last updated 2007-07-11).
How do I verify Diane Koslow's NPI record?
Cross-check NPI 1851500391 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-11.