| Vendor Name |
| 845 Design Group P.C. |
| Accurate Group Inc. |
| Accurate Group, Inc. |
| Advocate Medical Group |
| AECOM Technical Services, Inc. |
| Andrews Engineering, Inc. |
| Applied Communications Group, Inc. |
| Applied Technologies Inc. |
| Ardmore Associates |
| Associated Electrical |
| Atlas Engineering Group, Ltd. |
| ATS Ltd |
| Ayres Associates |
| Bailey Edward Design |
| Banyon American AutoMatrix |
| Baxter & Woodman, Inc. |
| Beacon SSI, Inc. |
| BLACK & VEATCH CORPORATION |
| Bowman Consulting Group Ltd. |
| Bravo Company Engineering, Inc. |
| Burns & McDonnell |
| C. Acitelli Heating & Piping Contractors, Inc. |
| Cardno, Inc. |
| Carollo Engineers, Inc. |
| Caseys Body Shop Inc |
| Catalyst Consulting Group, Inc. |
| CCS International, Inc. |
| Civil & Environmental Consultants, Inc. |
| Civil Design, Inc. |
| Civiltech Engineering, Inc. |
| CKL Engineers |
| Clark Dietz, Inc. |
| Control Point Engineering LLC |
| CTLGroup |
| Deuchler Environmental, Inc. |
| Dixon Engineering, Inc. |
| DLZ Illinois |
| Doyle & Associates |
| Earles Architects and Associates |
| ECS Midwest, LLC |
| Engineering Resource Associates, Inc |
| Eriksson Engineering Associates |
| Fehr Graham |
| FGK Services Inc. |
| GAI Consultants, Inc. |
| Gandhi and Associates, Inc. |
| Globetrotters Engineering Corporation |
| Globetrotters Engineering Corporation |
| GLOGER ENGINEERS LIMITED |
| Greengard, Inc. |
| GSG Consultants, Inc. |
| Hampton, Lenzini and Renwick, Inc. |
| Hazelette, Inc. d/b/a Staff Augmenters |
| HNTB Corporation |
| Horner & Shifrin, Inc. |
| Illinois Construction & Environme |
| J.A. Watts, Inc. |
| KALETECH LLC |
| Kapur & Associates, Inc. |
| Kenig, Lindgren, O'Hara, Aboona, Inc. |
| KLUBER INC |
| LIGHTNING POWER |
| M & J Asphalt Paving Company, Inc. |
| Main Architecture |
| Manhard Consulting |
| Manhard Consulting, Ltd. |
| Marie Daniel Group LLC |
| Millennia Professional Services |
| Orion Engineers, LLC |
| PARSONS |
| Parsons Brinckerhoff |
| Parsons Brinckerhoff Inc. |
| Patrick Engineering |
| Pentegra Systems LLC |
| PFB Architects, LLC |
| Phoenix Fabricators and Erectors, Inc. |
| Planning Resources Inc. |
| Planning Resources Inc. |
| Primera Engineers, Ltd. |
| RATIO States, PLLC dba RATIO States, LLC |
| RJN Group, Inc. |
| RME (Rubinos & Mesia Engineers, Inc.) |
| RTM Engineering Consultants |
| SCS Engineers |
| Single Source Industrial Coatings |
| Staples Technology Solutions |
| Strand Associates, Inc. |
| Syska Hennessy Group, Inc. |
| T&T Reproductions and Supplies |
| THE BEMNET GROUP, INC |
| Thomas Engineering Group, LLC |
| United Consulting Engineers, Inc. |
| Virtual Energy Solutions |
| Wight & Company |