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

Michael L Korthals, O.D.

Optometrist in Mason City, IA · enumerated 2006.

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

National Provider Identifier

1407880883

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Registry record

Entity type Individual (Type 1)

Name Michael L Korthals

Credential O.D.

Sex Male

Practice address Mason City, IA, 50401

Phone (641) 424-0780

Fax (641) 424-2345

Enumeration date Jul 10, 2006

Last updated in NPPES Dec 14, 2023

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

Taxonomy & licenses

152W00000X Optometrist Eye and Vision Services Providers · License 02146 (IA) Primary

OD · Doctor of Optometry: A licensed optometrist providing primary vision care, eye exams, and corrective lenses. About the OD credential

Other identifiers

Identifier	Type	State	Issuer
5178720001	Other	IA	DMERC
1204016	Medicaid	IA	-
42149949950401	Other	IA	TRICARE
IA0101	Other	IA	JOHN DEERE
35096	Other	IA	BLUE CROSS & BLUE SHIELD
P00135209	Other	IA	RR MEDICARE

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.

Read the full guide → Validate an NPI →

Frequently asked questions

Is NPI 1407880883 active?

Yes, as of the latest NPPES snapshot, NPI 1407880883 is active (record last updated 2023-12-14).

How do I verify Michael Korthals's NPI record?

Cross-check NPI 1407880883 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 2023-12-14.