DR. MARK CHRISTOPHER GILLIS MD
NPI 1992806509
Family Medicine in Itasca, IL
About Dr. Mark Christopher Gillis Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. MARK CHRISTOPHER GILLIS MD (NPI 1992806509) is an individual family medicine provider in Itasca, Illinois, licensed in Illinois (036078671) and active in the NPI registry since September 2006. He is enrolled in Medicare PECOS.
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 2
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Dr. Mark Christopher Gillis Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
2Medicare enrollment records show Mark Gillis reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Downers Grove, IL 60515
- Reassigned Medicare billing, Illinois enrollment
- 1,061 clinicians in this Medicare group
Carol Stream, IL 60122
- Reassigned Medicare billing, Illinois enrollment
- 1,664 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.
Areas of Expertise CMS Part B claims 39
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 60143 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Referred Medical Equipment & Supplies CMS DME claims 5
Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.
Other Providers at the Same Location NPPES 9
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
ITASCA, IL 60143
ITASCA, IL 60143
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 Mark Gillis's NPI number?
The NPI number for Mark Gillis is 1992806509. It was assigned to this individual provider in the NPPES registry on September 26, 2006.
Where is Mark Gillis located?
Mark Gillis practices at 1300 N Arlington Heights Rd Ste 130, Itasca, IL 60143. The listed phone number is (847) 871-4540.
What is Mark Gillis's specialty?
The primary specialty registered for this NPI is Family Medicine with taxonomy code 207Q00000X.
Is Mark Gillis enrolled in Medicare?
Yes. Mark Gillis is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Mark Gillis's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mark Gillis reassigns Medicare benefits to 2 organizations: Dupage Medical Group Ltd (Downers Grove, IL) and Central Dupage Physician Group (Carol Stream, IL). 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 Mark Gillis's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Mark Gillis was last updated on August 31, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 years 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.