Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mr. Mark Warren Olthoff, MSW

Clinical Social Worker in Rockford, MI · enumerated 2007.

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

National Provider Identifier

1073736484

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Registry record

Entity type Individual (Type 1)

Name Mr. Mark Warren Olthoff

Credential MSW

Sex Male

Practice address 10075 Northland Dr Ne, Rockford, MI, 49341

Phone (616) 866-0265

Fax (616) 866-0991

Enumeration date Apr 11, 2007

Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

1041C0700X Clinical Social Worker Behavioral Health & Social Service Providers · License 6801035615 (MI) 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

How do I verify Mark Olthoff's NPI record?

Cross-check NPI 1073736484 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Is NPI 1073736484 active?

Yes, as of the latest NPPES snapshot, NPI 1073736484 is active (record last updated 2007-07-08).

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.