| Operating Engineers Local 77 Pension Fund | Related tax-exempt org | Providing retirement benefits | MD | 526038506 |
| Operating Engineers Local 77 Apprenticeship Fund | Related tax-exempt org | Providing training benefits | MD | 526053812 |
| Operating Engineers Local 77 Individual Account Plan | Related tax-exempt org | Providing retirement benefits | MD | 522241121 |
| Operating Engineers Local 77 | Related tax-exempt org | Organizing workers | MD | 530088596 |
| 3 C Drilling LLC | Related taxable corporation/trust | — | — | — |
| A&F Siteworks LLC | Related taxable corporation/trust | — | — | — |
| Aaron Enterprises | Related taxable corporation/trust | — | — | — |
| Accurate Crane Rental | Related taxable corporation/trust | — | — | — |
| Aggregate Industries M | Related taxable corporation/trust | — | — | — |
| AJAY Glass | Related taxable corporation/trust | — | — | — |
| ALL Crane Rental of PA | Related taxable corporation/trust | — | — | — |
| ALL Mechanical and PLU | Related taxable corporation/trust | — | — | — |
| American Combustion In | Related taxable corporation/trust | — | — | — |
| Anchor Construction CO | Related taxable corporation/trust | — | — | — |
| Andis LLC | Related taxable corporation/trust | — | — | — |
| August Winter&sons INC | Related taxable corporation/trust | — | — | — |
| Badger Daylighting COR | Related taxable corporation/trust | — | — | — |
| BAI Excavating LLC | Related taxable corporation/trust | — | — | — |
| Baltimore PILE Driving | Related taxable corporation/trust | — | — | — |
| Barexinc | Related taxable corporation/trust | — | — | — |
| Barnhart Crane and RIG | Related taxable corporation/trust | — | — | — |
| Beeghly Tree | Related taxable corporation/trust | — | — | — |
| Beltway Paving of SOUT | Related taxable corporation/trust | — | — | — |
| Berco Industrial INC | Related taxable corporation/trust | — | — | — |
| Berkel & Company Contr | Related taxable corporation/trust | — | — | — |