| Northwestern Medical Faculty Foundation | Chicago | 4,503 |
| Endeavor Health Medical Group | Evanston | 3,350 |
| Advocate Health and Hospitals Corporation | Chicago | 3,118 |
| Athletico Ltd | Ottawa | 2,200 |
| Osf Multi-Specialty Group | Morton | 2,114 |
| Select Rehabilitation, LLC | Glenview | 2,046 |
| University of Chicago | Chicago | 1,712 |
| Carle Health Care Incorporated | Urbana | 1,666 |
| Rush University Medical Group | Chicago | 1,551 |
| Dupage Medical Group Ltd | Winfield | 1,322 |
| The Board of Trustees of the University of Illinois | Chicago | 1,150 |
| Central Dupage Physician Group | Geneva | 1,080 |
| Loyola University Medical Center | Maywood | 953 |
| The University of Chicago Medical Center | Chicago | 915 |
| Select Outpatient Services Inc | Glenview | 805 |
| Cook County | Chicago | 788 |
| Springfield Clinic, LLP | Springfield | 687 |
| Illinois Bone and Joint Institute, LLC | Gurnee | 604 |
| Orthomidwest, PLLC | Rockford | 547 |
| Rockford Health Physicians | Rockford | 521 |
| Cepamerica Illinois LLP | Arlington Heights | 499 |
| Fairview Heights Medical Group SC | Alton | 444 |
| North American Partners in Anesthesia Illinois LLC | Berwyn | 431 |
| Blessing Hospital | Quincy | 421 |
| Sarah Bush Lincoln Health Center | Altamont | 419 |
| Northstar Anesthesia of Illinois, LLC | Chicago Heights | 409 |
| Swedishamerican Hospital | Belvidere | 389 |
| Methodist Medical Center of Illinois | Peoria | 382 |
| Ivyrehab Physical Therapy, Occupational Therapy and Speech Language PA | Joliet | 376 |
| Rci (Wrs) LLC | Oak Park | 360 |
| Southern Illinois Medical Services Nfp | Carterville | 334 |
| Comprehensive Therapeutics Ltd | La Salle | 326 |
| Prime Healthcare Illinois Medical Group LLC | Chicago | 322 |
| Siu Physicians and Surgeons Inc | Springfield | 314 |
| Edgewood Clinical Services P.C. | Orland Park | 310 |
| Providence Medical Institute | Park Ridge | 288 |
| Theoria Medical | East Moline | 284 |
| 24 on Physicians PC | Herrin | 272 |
| Carle West Physician Group Inc | Bloomington | 271 |
| Physicians Immediate Care North Chicago LLC | Aurora | 257 |
| Adventist Health Partners, Inc. | Lombard | 255 |
| Mount Sinai Community Foundation | Chicago | 248 |
| Athletic and Therapeutic Institute of Naperville, LLC | Wheaton | 241 |
| Oak Street Health Physicians Group PC | Blue Island | 229 |
| Quincy Physicians and Surgeons Clinic, PLLC | Quincy | 223 |
| Advanced Physical Therapy Services, Ltd. | Bloomington | 223 |
| Midwest Express Care 2, Inc | Willowbrook | 222 |
| Christie Clinic, PLLC | Champaign | 220 |
| Hshs Medical Group Inc | O Fallon | 219 |
| Vitae Health Medical Illinois, PLLC | Lincolnshire | 215 |
| Central Illinois Radiological Associates Ltd | Kewanee | 209 |
| Riverside Health System | Willmington | 199 |
| Cgh Medical Center | Sterling | 197 |
| Functional Pathways Preferred of Tennessee LLC | Northbrook | 196 |
| Cep America-Illinois Hospitalists, LLP | Alton | 196 |
| Access Community Health Network | Arlington Heights | 182 |
| Midwest Anesthesia Providers SC | Alton | 182 |
| Freeport Memorial Hospital | Freeport | 178 |
| Dpt Holdings LLC | Lisle | 175 |
| Decatur Memorial Hospital | Decatur | 174 |
| Athletic and Therapeutic Institute of Bourbonnais, LLC | Bourbonnais | 167 |
| Bonaventure Medical Foundation LLC | Bartlett | 167 |
| Memorial Physician Services | Chatham | 165 |
| Gibson Community Hospital Association | Paxton | 163 |
| Integrated Rehab Consultants LLC | Marseilles | 161 |
| Rockford Psychiatric Medical Services SC | Chicago | 160 |
| Good Samaritan Regional Health Center | Mount Vernon | 156 |
| Associated Anesthesiologists SC | Peoria | 155 |
| University Anesthesiologists SC | Chicago | 151 |
| Lurie Children's Medical Group Inc. | Chicago | 151 |
| Pinnacle Dermatology SC | Chicago | 148 |
| Deaconess Illinois Specialty Clinic, Inc. | Harrisburg | 148 |
| Hoopeston Community Memorial Hospital | Hoopeston | 144 |
| Insight Chicago Inc | Chicago | 141 |
| Cmc Healthcare LLC | Crystal Lake | 141 |
| Uropartners LLC | Hinsdale | 138 |
| Erie Family Health Center, Inc | Evanston | 138 |
| Board of Trustees of Southern Illinois University | Quincy | 137 |
| Memorial Medical Center | Springfield | 136 |
| City of Hope Medical Group of Illinois PLLC | Zion | 129 |
| Midwest Post Acute Care PLLC | Paxton | 127 |
| Loyola Medical Group LLC | Berwyn | 127 |
| Graham Hospital Association | Canton | 126 |
| Lawndale Christian Health Center | Chicago | 123 |
| Illinois Diagnostic and Interventional Radiology PLLC | Glenview | 123 |
| Ora Orthopedics PC | Moline | 122 |
| Illinois Luna Care Physical Therapy LLC | Naperville | 121 |
| Physician Services Corporation of Southern Illinois Inc | Salem | 120 |
| Southern Illinois Healthcare Foundation Inc | East Saint Louis | 119 |
| Midwest Anesthesia Partners LLC | Hinsdale | 119 |
| Nephrology Associates of Northern Illinois Ltd | Algonquin | 117 |
| Clarity Clinic LLC | Chicago | 117 |
| Morris Hospital | Seneca | 115 |
| Illinois Gastroenterology Group LLC | Arlington Heights | 115 |
| Midwestern University | Downers Grove | 115 |
| St Marys Hospital Centralia Illinois | Centralia | 114 |
| Minuteclinic Diagnostic of Illinois PLLC | Worth | 110 |
| Richland Memorial Hospital Inc | Olney | 109 |
| Ucm Medical Group Sub LLC | Harvey | 109 |
| Apex Physical Therapy, LLC | Freeburg | 105 |