| Chenz, Inc. | Smithtown | NY | Subcontractor |
| Chickasaw Telecom, Inc. | Oklahoma City | OK | $0 |
| Chinchor Electric, Inc. | Orange City | FL | $0 |
| Chr-eyton Electric Co. Inc. | Little Rock | AR | $0 |
| Christenson Electric, Inc. | Portland | OR | Subcontractor |
| Christianbelle Electric, Inc. | Hesperia | CA | Subcontractor |
| Christopher J Bruder | Staten Island | NY | $0 |
| Circle City Telcom Inc. | Taylor | AL | $0 |
| Cir Electrical Construction Corp. | Grand Island | NY | $0 |
| City Electric Co. | Ridgefield | WA | Subcontractor |
| CJ'S Sales And Service Of Ocala, Inc. | Ocala | FL | $0 |
| Claypool Electric, Inc. | Lancaster | OH | $0 |
| C & L Contractors, Ltd. | Burke | VA | Subcontractor |
| Clear Communications Inc. | Silver Spring | MD | $0 |
| Clennon Electric, Inc. | Wilmington | IL | $0 |
| Cleveland Electric Company | Atlanta | GA | Subcontractor |
| C. L. Felts And Company, Inc. | Pylesville | MD | Subcontractor |
| Clinton Electric Inc. | Bonnie | IL | Subcontractor |
| CMD Electric Inc. | Ontario | CA | Subcontractor |
| CMX Services LLC | Carlsbad | NM | Subcontractor |
| Coastal Fire And Safety, LLC | Vancleave | MS | $0 |
| Cochran, Inc. | Seattle | WA | Subcontractor |
| Cogburn Bros, Inc. | Jacksonville | FL | $0 |
| Collins Electrical Co. Inc. | Stockton | CA | Subcontractor |
| Coltrane Systems LLC | Saint Louis | MO | Subcontractor |
| Comeau Electric Inc. | Grand Forks | ND | $0 |
| Commercial Electric Of Long Beach Inc. | Long Beach | MS | Subcontractor |
| Commonwealth Electric Company Of The Midwest | Lincoln | NE | Subcontractor |
| Commonwealth Electric, L.L.C | Mechanicsvlle | VA | Subcontractor |
| Communication Company Of South Bend Inc. | South Bend | IN | $0 |
| Communication Consulting Services, Inc. | Honolulu | HI | $0 |
| Communication Innovators, Inc. | Pleasant Hill | IA | $0 |
| Communications, Cabling & Networking, Inc. | Brookfield | WI | $0 |
| Communications Solution Corp. | Guaynabo | PR | $0 |
| Communications Solutions, Inc. | Jacksonville | FL | $0 |
| Communication Wiring Specialists Inc. | San Diego | CA | $0 |
| Comnet Commincations LLC | Bethel | CT | Subcontractor |
| Competitive Edge Partners & Consulting LLC | Altamonte Springs | FL | Subcontractor |
| Complete Hearing Solutions LLC | Oldsmar | FL | $0 |
| Complete Network Solutions, Inc. | Gainesville | FL | $0 |
| Computer Power Systems, LLC | Newark | DE | $0 |
| Computer Support Systems, Inc. | Decatur | AL | Subcontractor |
| Comp-utility Corp. | Austin | TX | $0 |
| Comtech, Inc. | Billings | MT | Subcontractor |
| Concor Networks, Inc. | Linthicum Heights | MD | Subcontractor |
| Conrad's Big 'C' Electric, Inc. | Rapid City | SD | $0 |
| Consolidated Contracting & Engineering, LLC | Anchorage | AK | Subcontractor |
| Consolidated Electrical Construction, Inc. | San Francisco | CA | Subcontractor |
| Consolidated Electric Service, Inc. | Helotes | TX | Subcontractor |
| Consolidated Wiring LLC | Huntsville | AL | $0 |
| Contemporary Electrical Services Inc. | Reston | VA | Subcontractor |
| Conti LLC | Sterling Heights | MI | Subcontractor |
| Continental Electrical Construction Company LLC | Oak Brook | IL | Subcontractor |
| Contra Costa Electric, Inc. | Martinez | CA | Subcontractor |
| Control Concepts Inc. | Texarkana | AR | Subcontractor |
| Control Management, Inc. | Omaha | NE | $0 |
| Control Solutions Inc. | Wyoming | MI | $0 |
| Control Technologies, Inc. | Lubbock | TX | $0 |
| Cook Electrical Of Jacksonville, Inc. | Jacksonville | FL | $0 |
| Corbins LLC | Phoenix | AZ | Subcontractor |
| County Electric, LLC | Ottawa | OH | $0 |
| Cove Electric, Inc.Palm Desert, CA · UEI DZ3NY3PJK3Y4 | Palm Desert | CA | $0 |
| Cove Electric, Inc.Edgewood, MD · UEI N3UMC91J7GX1 | Edgewood | MD | $0 |
| Coyote Building Solutions, Inc. | Sacramento | CA | Subcontractor |
| CP3 Energy Systems Inc. | Old Forge | PA | Subcontractor |
| Craig S Danielson Inc. | Omaha | NE | Subcontractor |
| Crawford Technical Services, Inc. | Gambrills | MD | $0 |
| CRC Associates Inc. | South Plainfield | NJ | $0 |
| Creative Audio Visual Group LLC | Ona | WV | $0 |
| Creative Cabling And Bertram Electric Corp. | Hicksville | NY | $0 |
| C & R Electrical Construction, Inc. | Astor | FL | Subcontractor |
| Cris Corporation, Electrical Systems | Shady Side | MD | $0 |
| Critical Electric Systems Group LLC | Plano | TX | $0 |
| Critical Power Electric, LLC | Houston | TX | Subcontractor |
| Crosstown Electrical & Data, Inc. | Irwindale | CA | $0 |
| CTS Construction Inc. | Cincinnati | OH | $0 |
| Cullen Electrical Contractors Inc. | Marshfield | MA | $0 |
| Cup Communications LLC | Monterey Park | CA | $0 |
| Cupertino Electric, Inc. | San Jose | CA | $0 |
| Current Connections, Inc. | West Palm Beach | FL | Subcontractor |
| Currentmaster Electric, LLC | Mantua | NJ | Subcontractor |
| Current Power Solutions LLC | Germantown | MD | Subcontractor |
| Current Solutions, LLC | Grand Junction | CO | $0 |
| Custom Computer Cable Inc. | Sterling | VA | Subcontractor |
| Custom Controls Corporation | Fife | WA | $0 |
| Cutting Edge Communications LLC | Battletown | KY | Subcontractor |
| C. W. Campbell Electric, Inc. | Corpus Christi | TX | Subcontractor |
| C W Electrical, Inc. | Chico | CA | Subcontractor |
| C-wing Services, Inc. | Kodiak | AK | $0 |
| Cynergy Electric Company, Inc. | Crofton | MD | Subcontractor |
| Cyprium Solutions Inc. | East Petersburg | PA | $0 |
| Cyson Technology Group LLC | Houston | TX | $0 |
| Dagle Electrical Construction Corp. | Wilmington | MA | $0 |
| Daidone Electric, Inc. | Newark | NJ | Subcontractor |
| Dakota Sound Systems Inc. | Bismarck | ND | $0 |
| Danard Electric, Inc. | Tacoma | WA | Subcontractor |
| Dantek Systems, Inc. | El Paso | TX | $0 |
| Dark To Light Fiber Optics, LLC | Tucson | AZ | $0 |
| Darwin2000 Inc. | Mount Jackson | VA | Subcontractor |
| Data Cabling Service, Inc. | Boise | ID | $0 |
