| 1800 MCDONOUGH ROAD SURGERY CENTER LLC | Organization | HOFFMAN ESTATES |
| 1915-25 95TH ST., LLC | Organization | CHICAGO |
| 25 EAST SAME DAY SURGERY LLC | Organization | CHICAGO |
| AANCHOR HEALTH CENTER, LTD. | Organization | GLEN ELLYN |
| ACCESS HEALTH CARE CENTER | Organization | DES PLAINES |
| ACCESS HEALTH CENTER, LTD. | Organization | DOWNERS GROVE |
| ACCREDITED AMBULATORY CARE, LLC | Organization | CHICAGO |
| ACU HEALTH CENTER, LTD. | Organization | HINSDALE |
| ADVA-MED SURGICAL ASSOCIATION INC | Organization | OAK LAWN |
| ADVANCED AESTHETICS SURGERY & LASER CENTER, P.C. | Organization | CHAMPAIGN |
| ADVANCED AMBULATORY SURGICAL CENTER, INC | Organization | CHICAGO |
| ADVANCED ANKLE & FOOT CARE CENTER LTD | Organization | NAPERVILLE |
| ADVANCED CARE PROVIDERS | Organization | CHICAGO |
| ADVANCED PODIATRIC SURGERY SERVICES | Organization | WAUKEGAN |
| ADVANCED PODIATRIC SURGICAL SERVICES LLC | Organization | WAUKEGAN |
| ADVOCATE CONDELL AMBULATORY SURGERY CENTER, LLC | Organization | LIBERTYVILLE |
| ADVOCATE HEALTH AND HOSPITALS CORPORATION | Organization | NAPERVILLE |
| ADVOCATE HEALTH AND HOSPITALS CORPORATION | Organization | CHICAGO |
| ADVOCATE SOUTHWEST AMBULATORY SURGERY CENTER LLC | Organization | TINLEY PARK |
| AESTHETIC & RECONSTRUCTIVE PLASTIC SURGERY INSTITUTE, S.C. | Organization | SWANSEA |
| AESTHETIC ANESTHESIA, LLC | Organization | GLENVIEW |
| AESTHETIC SURGERY ASSOCIATES | Organization | NAPERVILLE |
| AFFILIATED SURGICARE,LTD. | Organization | CHICAGO |
| AGHAPY SURGICAL CENTER SC | Organization | BARRINGTON |
| AIDEN CENTER FOR DAY SURGERY LLC | Organization | ADDISON |
| ALGONQUIN ROAD SURGERY CENTER, LLC | Organization | LAKE IN THE HILLS |
| ALLISON MULHERN, APRN | Individual | CHICAGO |
| ALTON SURGICAL FACILITY, P.C. | Organization | ALTON |
| AMBER LASER LLC | Organization | JOLIET |
| AMBULATORY SURGERY CENTER OF CENTRALIA | Organization | CENTRALIA |
| AMBULATORY SURGERY CENTER OF CENTRALIA, LLC | Organization | CENTRALIA |
| AMBULATORY SURGERY CENTERS OF CHICAGO | Organization | CHICAGO |
| AMBULATORY SURGICAL CARE FACILITY, LLC | Organization | AURORA |
| AMBULATORY SURGICENTER OF DOWNERS GROVE | Organization | DOWNERS GROVE |
| AMERICAN COLONOSCOPY AND ENDOSCOPY CENTER | Organization | GENEVA |
| AMERICAN FOOT CARE CENTER INC | Organization | HOMEWOOD |
| AMERICAN HEALTHCARE SYSTEMS ILLINOIS LLC | Organization | GLEN CARBON |
| AMERICAN SURGERY CARE | Organization | WOOD DALE |
| AMERICAN SURGICAL SERVICES, INC | Organization | CHICAGO |
| AMERICAN WOMENS MEDICAL GROUP | Organization | CHICAGO |
| ANDERSON SURGERY CENTER LLC | Organization | EDWARDSVILLE |
| ANKLE & FOOT SURGICENTER | Organization | NILES |
| ANN & ROBERT H. LURIE CHILDREN'S HOSPITAL OF CHICAGO | Organization | NORTHBROOK |
| ANTI AGING SURGICAL CENTER | Organization | CHICAGO |
| APM SURGICAL GROUP, LTD | Organization | CHICAGO |
| APOLLO HEALTH CENTER, LTD. | Organization | DES PLAINES |
| APOLLO SURGICAL CENTER, LLC | Organization | ARLINGTON HEIGHTS |
| ARETE CORPORATION | Organization | WHEELING |
| ARLINGTON HEIGHTS SPINE PAIN AND ORTHOPEDICS | Organization | ARLINGTON HEIGHTS |
| ARLINGTON HEIGHTS SURGERY CENTER, LLC | Organization | ARLINGTON HEIGHTS |
| ARLINGTON MULTI SPECIALTY MEDICAL CENTER | Organization | ARLINGTON HEIGHTS |
| ASCENSION SAINT JOSEPH MSK JV, LLC | Organization | CHICAGO |
| ASSOCIATED PHYSICIANS GROUP LTD | Organization | O FALLON |
| ASSOCIATED SURGICAL CENTER LLC | Organization | ARLINGTON HEIGHTS |
| AYESHA AKBAR, M. D ., S.C. | Organization | FRANKFORT |
| BARRINGTON OUTPATIENT LLC | Organization | BARRINGTON |
| BARRINGTON PAIN AND SPINE INSTITUTE, LLC | Organization | BARRINGTON |
| BEL CLAIR AMBULATORY SURGICAL TREATMENT CENTER, LTD. | Organization | BELLEVILLE |
| BELLEVILLE SURGICAL CENTER LTD | Organization | BELLEVILLE |
| BELLEVILLE SURGICAL CENTER LTD | Organization | BELLEVILLE |