Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mark Dewitt Lanyon, PHD

Addiction (Substance Use Disorder) Counselor in Wilmington, DE · enumerated 2007.

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

National Provider Identifier

1417008137

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Registry record

Entity type Individual (Type 1)

Name Mark Dewitt Lanyon

Credential PHD

Sex Male

Practice address 2814 W 2nd St, Wilmington, DE, 19805

Phone (302) 472-0381

Fax (302) 472-0392

Enumeration date Jan 16, 2007

Last updated in NPPES Sep 11, 2025

Taxonomy & licenses

103TB0200X Cognitive & Behavioral Psychologist Behavioral Health & Social Service Providers Secondary

101YA0400X Addiction (Substance Use Disorder) Counselor Behavioral Health & Social Service Providers Primary

PHD · Doctor of Philosophy: A doctoral degree; in healthcare often held by clinical psychologists and researchers. About the PHD credential

Other identifiers

Identifier	Type	State	Issuer
1000024329	Medicaid	DE	-
PC002510	Other	PA	PROF COUNSELOR LICENSE#

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 Mark Lanyon?

Mark Lanyon is registered in NPPES with the primary taxonomy of Addiction (Substance Use Disorder) Counselor. 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 2025-09-11.