| Smart Local 265 Pension | Related tax-exempt org | Pension fund | IL | 366168611 |
| Smart Local 265 Supplemental Retirement Plan | Related tax-exempt org | Annuity fund | IL | 363911499 |
| Smart Local 265 LMCC | Related tax-exempt org | Labor management cooperation committee | IL | 364146794 |
| Smart Local 265 Education | Related tax-exempt org | Training fund | IL | 366148078 |
| Smart Local 265 | Related tax-exempt org | Labor union | IL | 362368182 |
| A M S Mechanical Systems | Related taxable corporation/trust | — | — | — |
| A T Mechanical LLC | Related taxable corporation/trust | — | — | — |
| A-1 Roofing CO | Related taxable corporation/trust | — | — | — |
| Admiral Mechanical Services | Related taxable corporation/trust | — | — | — |
| Advance Mechanical Systems In | Related taxable corporation/trust | — | — | — |
| AIR Comfort Corp | Related taxable corporation/trust | — | — | — |
| AIR FLOW CO INC | Related taxable corporation/trust | — | — | — |
| AIR Quality INC | Related taxable corporation/trust | — | — | — |
| AIR RITE Heating & Cooling | Related taxable corporation/trust | — | — | — |
| AIR-DUCT MFG & Supply INC | Related taxable corporation/trust | — | — | — |
| Airtech Heating & AC Corp | Related taxable corporation/trust | — | — | — |
| Albert J Wagner & Sonllc | Related taxable corporation/trust | — | — | — |
| ALL American Roofing Coinc | Related taxable corporation/trust | — | — | — |
| ALL TECH Mechanical Services I | Related taxable corporation/trust | — | — | — |
| Allied Power LLC | Related taxable corporation/trust | — | — | — |
| Allstate Metal FAB | Related taxable corporation/trust | — | — | — |
| Althoff Industries INC | Related taxable corporation/trust | — | — | — |
| Amber Mechanical Contractors I | Related taxable corporation/trust | — | — | — |
| AMCO INC | Related taxable corporation/trust | — | — | — |
| American AIR MECH SERV INC | Related taxable corporation/trust | — | — | — |