Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mark D. Hollowitsch, CSAC

Addiction (Substance Use Disorder) Counselor in La Crosse, WI · enumerated 2006.

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

National Provider Identifier

1245270172

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Registry record

Entity type Individual (Type 1)

Name Mark D. Hollowitsch

Credential CSAC

Sex Male

Practice address 212 11th Street S., La Crosse, WI, 54601

Phone (608) 392-9555

Fax (608) 785-0002

Enumeration date Jun 8, 2006

Last updated in NPPES Dec 20, 2011

Taxonomy & licenses

101YA0400X Addiction (Substance Use Disorder) Counselor Behavioral Health & Social Service Providers · License 1631 (WI) Primary

101YA0400X Addiction (Substance Use Disorder) Counselor Behavioral Health & Social Service Providers · License 1631-132 (WI) Secondary

Other identifiers

Identifier	Type	State	Issuer
39380200	Medicaid	WI	-

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

How do I verify Mark Hollowitsch's NPI record?

Cross-check NPI 1245270172 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Is NPI 1245270172 active?

Yes, as of the latest NPPES snapshot, NPI 1245270172 is active (record last updated 2011-12-20).

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Gilda Winter Psychiatry Physician · La Crosse, WI NPI 1518949122 Janice Schreier Clinical Social Worker · La Crosse, WI NPI 1104063486

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-12-20.