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

Dr. O'Neal Alfred Walker

Clinical Psychologist in Rockville, MD · enumerated 2012.

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

National Provider Identifier

1336419563

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Registry record

Entity type Individual (Type 1)
Name Dr. O'Neal Alfred Walker
Sex Male
Practice address Rockville, MD, 20852
Phone (240) 426-5859
Fax (301) 972-1318
Enumeration date Jan 4, 2012
Last updated in NPPES Feb 13, 2025

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

Taxonomy & licenses

103TC0700X Clinical Psychologist Behavioral Health & Social Service Providers · License 04000 (MD) Primary

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 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.
What specialty is O'Neal Walker?
O'Neal Walker is registered in NPPES with the primary taxonomy of Clinical Psychologist. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-02-13.