NPI Portal NPI Lookup & Verification

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

Lynn Sewester Underwood, MA, LCPC

Professional Counselor in O Fallon, IL · enumerated 2018 · practices at Illinois Mentor.

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

National Provider Identifier

1700353679

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Registry record

Entity type Individual (Type 1)
Name Lynn Sewester Underwood
Credential MA, LCPC
Sex Female
Practice address O Fallon, IL, 62269
Phone (618) 514-1154
Enumeration date Oct 30, 2018
Last updated in NPPES Nov 17, 2025

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

Taxonomy & licenses

101Y00000X Counselor Behavioral Health & Social Service Providers · License 180.011860 (IL) Secondary
101YP2500X Professional Counselor Behavioral Health & Social Service Providers · License 180.011860 (IL) 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

Is NPI 1700353679 active?
Yes, as of the latest NPPES snapshot, NPI 1700353679 is active (record last updated 2025-11-17).
How do I verify Lynn Underwood's NPI record?
Cross-check NPI 1700353679 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-11-17.