NPI Portal NPI Lookup & Verification

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

Mr. John Thomas Madsen, CADC II

Addiction (Substance Use Disorder) Counselor in Grass Valley, CA · enumerated 2007.

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

National Provider Identifier

1194946582

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Registry record

Entity type Individual (Type 1)
Name Mr. John Thomas Madsen
Credential CADC II
Sex Male
Practice address Grass Valley, CA, 95945
Phone (530) 273-9541
Fax (530) 273-7740
Enumeration date May 1, 2007
Last updated in NPPES May 5, 2011

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

Taxonomy & licenses

324500000X Substance Abuse Rehabilitation Facility Residential Treatment Facilities Secondary
101YA0400X Addiction (Substance Use Disorder) Counselor Behavioral Health & Social Service Providers · License A8539205 (CA) 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

What is the NPI number for John Madsen?
The National Provider Identifier (NPI) for John Madsen is 1194946582, a Type 1 (individual) record in the CMS NPPES registry.
Where does John Madsen practice?
The practice location on file with NPPES is in Grass Valley, CA. Providers can have multiple locations; NPPES lists the primary practice address.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-05-05.