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

Larissa Niessen, MS CCC-SLP/L

Speech-Language Pathologist in Fullerton, CA · enumerated 2020 · practices at Fullerton Elementary School District.

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

National Provider Identifier

1780299180

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Registry record

Entity type Individual (Type 1)

Name Larissa Niessen

Credential MS CCC-SLP/L

Sex Female

Practice address Fullerton, CA, 92833

Phone (714) 447-7745

Enumeration date Sep 11, 2020

Last updated in NPPES Sep 11, 2020

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

Taxonomy & licenses

235Z00000X Speech-Language Pathologist Speech, Language and Hearing Service Providers · License 23092 (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 Larissa Niessen?

The National Provider Identifier (NPI) for Larissa Niessen is 1780299180, a Type 1 (individual) record in the CMS NPPES registry.

Where does Larissa Niessen practice?

The practice location on file with NPPES is in Fullerton, 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 2020-09-11.