Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Sean William Marquis, MD

Emergency Medicine Physician in Janesville, WI · enumerated 2009.

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

National Provider Identifier

1053554089

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Registry record

Entity type Individual (Type 1)

Name Sean William Marquis

Credential MD

Sex Male

Practice address 1000 Mineral Point Ave, Janesville, WI, 53548

Phone (608) 756-6611

Fax (608) 756-6177

Enumeration date Apr 7, 2009

Last updated in NPPES Apr 16, 2026

Taxonomy & licenses

207P00000X Emergency Medicine Physician Allopathic & Osteopathic Physicians · License 46924-20 (WI) Primary

207P00000X Emergency Medicine Physician Allopathic & Osteopathic Physicians · License 4301099517 (MI) Secondary

207P00000X Emergency Medicine Physician Allopathic & Osteopathic Physicians · License 036132727 (IL) Secondary

207P00000X Emergency Medicine Physician Allopathic & Osteopathic Physicians · License 35097788 (OH) Secondary

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
1053554089	Medicaid	WI	-

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 this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

What specialty is Sean Marquis?

Sean Marquis is registered in NPPES with the primary taxonomy of Emergency Medicine Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-04-16.