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

John Mark Demay, MD

Q: What is the NPI number for John Demay?

The National Provider Identifier (NPI) for John Demay is 1366447294, a Type 1 (individual) record in the CMS NPPES registry.

Dermatology Physician in Sioux City, IA · enumerated 2005 · practices at Dermatology Associates of Siouxland, PC.

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

National Provider Identifier

1366447294

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Registry record

Entity type Individual (Type 1)

Name John Mark Demay

Credential MD

Sex Male

Practice address Sioux City, IA, 51104

Phone (712) 277-9370

Fax (712) 252-4733

Enumeration date Jun 16, 2005

Last updated in NPPES Aug 16, 2016

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

Taxonomy & licenses

207N00000X Dermatology Physician Allopathic & Osteopathic Physicians · License 31906 (IA) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier	Type	State	Issuer
1366447294	Other	IA	MEDICARE INDIVIDUAL NPI
DT7736	Other	IA	MEDICARE RR GROUP PTAN
1417088907	Other	IA	WELLMARK GROUP NPI NUMBER
IB2763	Other	IA	MEDICARE GROUP PTAN
IB2763001	Other	IA	MEDICARE INDIVIDUAL PTAN

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

What is the NPI number for John Demay?

The National Provider Identifier (NPI) for John Demay is 1366447294, a Type 1 (individual) record in the CMS NPPES registry.

Where does John Demay practice?

The practice location on file with NPPES is in Sioux City, IA. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

Browse all →

David Grote Medical Physician Assistant · Sioux City, IA NPI 1164465019 Tod Knopik General Practice Dentistry · Sioux City, IA NPI 1154332450 Dermatology Associates of Siouxland, PC Specialist · Sioux City, IA NPI 1417088907

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2016-08-16.