SEAN WILLIAM MARQUIS MD
NPI 1053554089
Emergency Medicine in Janesville, WI
About Sean William Marquis Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
SEAN WILLIAM MARQUIS MD (NPI 1053554089) is an individual emergency medicine provider in Janesville, Wisconsin, licensed in Wisconsin (46924-20) and active in the NPI registry since April 2009. He is enrolled in Medicare PECOS, is affiliated with Mercy Health System Corp, and is a graduate of Other (2009).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 1
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Sean William Marquis Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
4Medicare enrollment records show Sean Marquis reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Janesville, WI 53548
- Reassigned Medicare billing, Wisconsin and Illinois enrollments
- Also billed through NPI 1598718603 (Illinois), NPI 1699728550 (Wisconsin)
- 1,155 clinicians in this Medicare group
Rockford, IL 61114
- Reassigned Medicare billing, Illinois enrollment
- 1,375 clinicians in this Medicare group
Harvard, IL 60033
- Reassigned Medicare billing, Illinois enrollment
- 382 clinicians in this Medicare group
Milwaukee, WI 53226
- Reassigned Medicare billing, Wisconsin enrollment
- 3,983 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Hospital Affiliations CMS Care Compare 2
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Mercy Health System Corp
Acute Care Hospitals · Janesville, WIMercy Walworth Hospital & Medical Center
Critical Access Hospitals · Lake Geneva, WIPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 53548 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
JANESVILLE, WI 53548
JANESVILLE, WI 53548
JANESVILLE, WI 53548
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Sean Marquis's NPI number?
The NPI number for Sean Marquis is 1053554089. It was assigned to this individual provider in the NPPES registry on April 7, 2009.
Where is Sean Marquis located?
Sean Marquis practices at 1000 Mineral Point Ave, Janesville, WI 53548. The listed phone number is (608) 756-6611.
What is Sean Marquis's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Sean Marquis enrolled in Medicare?
Yes. Sean Marquis is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Sean Marquis's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Sean Marquis reassigns Medicare benefits to 4 organizations: Mercy Health System Corporation (Janesville, WI), Rockford Health Physicians (Rockford, IL), Mercy Harvard Hospital Inc (Harvard, IL) and The Medical College Of Wisconsin, Inc. (Milwaukee, WI). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Sean Marquis's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is Sean Marquis affiliated with any hospitals?
According to CMS data, Sean Marquis is affiliated with Mercy Health System Corp and Mercy Walworth Hospital & Medical Center.
When was this NPI record last updated?
The NPPES record for Sean Marquis was last updated on April 16, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Sean William Marquis, MD · NPI 1053554089
Emergency Medicine physician in Janesville, Wisconsin. Individual provider, active in the CMS NPPES registry since April 7, 2009.
## Identity
- **NPI:** 1053554089 (Entity type: Individual)
- **Enumerated:** April 7, 2009
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** 46924-20 (Wisconsin)
- **Sole proprietor:** No
## Practice location
- **Address:** 1000 MINERAL POINT AVE, Janesville, WI 53548-2940
- **Phone:** (608) 756-6611 · **Fax:** (608) 756-6177
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 4 organizations under Medicare reassignment (form CMS-855R): Mercy Health System Corporation (NPI 1093768962, Janesville, WI); Rockford Health Physicians (NPI 1043242886, Rockford, IL); Mercy Harvard Hospital Inc (NPI 1427001445, Harvard, IL); The Medical College Of Wisconsin, Inc. (NPI 1699720086, Milwaukee, WI) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2009
## Record status
- **NPPES last updated:** April 16, 2026
- **Other identifiers:** Medicaid 1053554089 (WI)
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Source: [NPI Profile](https://npiprofile.com/npi/1053554089) · Data from the CMS NPPES public registry.