MR. MARK CHWAJOL M.D.
NPI 1356575690
Neurological Surgery in Chicago, IL
About Mr. Mark Chwajol M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MR. MARK CHWAJOL M.D. (NPI 1356575690) is an individual neurological surgery provider in Chicago, Illinois, licensed in Illinois (036.123878) and active in the NPI registry since May 2009. He is enrolled in Medicare PECOS, is affiliated with Osf Saint Elizabeth Mdl Ctr, and maintains 4 additional practice locations.
NPPES Registry Identity
Specialties & Licenses
Other Names 1
Secondary Practice Locations 4
Accepted Insurance
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
Mr. Mark Chwajol M.d. 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
6Medicare enrollment records show Mark Chwajol reassigns Medicare billing to 6 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Chicago, IL 60612
- Reassigned Medicare billing, Illinois enrollment
- 2,127 clinicians in this Medicare group
Chicago, IL 60608
- Reassigned Medicare billing, Illinois enrollment
- Medicare enrollment name: Mount Sinai Community Foundation
- 646 clinicians in this Medicare group
Lake Geneva, WI 53147
- Reassigned Medicare billing, Wisconsin and Illinois enrollments
- Also billed through NPI 1598718603 (Wisconsin)
- 271 clinicians in this Medicare group
Freeport, IL 61032
- Reassigned Medicare billing, Illinois enrollment
- 391 clinicians in this Medicare group
Freeport, IL 61032
- Reassigned Medicare billing, Illinois enrollment
- 478 clinicians in this Medicare group
Peoria, IL 61615
- Reassigned Medicare billing, Illinois enrollment
- 2,944 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 3
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.
Hospital Affiliations CMS Care Compare 3
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Osf Saint Elizabeth Mdl Ctr
Acute Care Hospitals · Ottawa, ILSaint Anthony Medical Center
Acute Care Hospitals · Rockford, ILMercy Health System Corp
Acute Care Hospitals · Janesville, WIPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 60612 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.
CHICAGO, IL 60612
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 Chwajol's NPI number?
The NPI number for Mark Chwajol is 1356575690. It was assigned to this individual provider in the NPPES registry on May 13, 2009. The provider is also known as Mr. Marek Chwajol M.D..
Where is Mark Chwajol located?
Mark Chwajol practices at 1740 W Taylor St, Chicago, IL 60612. The listed phone number is (886) 600-2273.
What is Mark Chwajol's specialty?
The primary specialty registered for this NPI is Neurological Surgery with taxonomy code 207T00000X.
Is Mark Chwajol enrolled in Medicare?
Yes. Mark Chwajol 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 Mark Chwajol's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mark Chwajol reassigns Medicare benefits to 6 organizations: Board Of Trustees Of The University Of Illinois (Chicago, IL), Mount Sinai Community Foundation Dba Sinai Medical Group (Chicago, IL), Mercy Health System Corporation (Lake Geneva, WI), Freeport Regional Health Care Foundation (Freeport, IL), Freeport Memorial Hospital (Freeport, IL) and 1 more organization, listed in the Medicare section above. 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 Chwajol's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Mark Chwajol accept?
Health plans from Anthem Blue Cross and Blue Shield, Dean Health Plan and MercyCare Health Plans list Mark Chwajol as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Mark Chwajol affiliated with any hospitals?
According to CMS data, Mark Chwajol is affiliated with Osf Saint Elizabeth Mdl Ctr, Saint Anthony Medical Center and Mercy Health System Corp.
When was this NPI record last updated?
The NPPES record for Mark Chwajol was last updated on June 30, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.