| Investment Trust Local 392 | Related tax-exempt org | Lease | OH | 237166422 |
| Plumbers PIPE Fitters & MES | Related tax-exempt org | Expenses | OH | 310727369 |
| Plumbers PIPE Fitters & MES | Related tax-exempt org | Expenses | OH | 310655223 |
| Plumbers PIPE Fitters & MES | Related tax-exempt org | School | OH | 310619811 |
| Mechanical Contractors Association | Related tax-exempt org | Associatio | OH | 310249290 |
| Plumbers PIPE Fitters & MES | Related tax-exempt org | Union | OH | 310474230 |
| Plumbers PIPE Fitters & MES | Related tax-exempt org | Expenses | OH | 842587991 |
| OHIO State Association of Plumbers | Related tax-exempt org | Reciprocit | OH | 340707601 |
| AC&R Specialists | Related taxable corporation/trust | Contractor | — | 421064284 |
| Advanced Facilities INC | Related taxable corporation/trust | Contractor | OH | 311475939 |
| Advanced Mechanical of Northern KY | Related taxable corporation/trust | Contractor | KY | 812647078 |
| Alpha Mechanical Service INC | Related taxable corporation/trust | Contractor | KY | — |
| Artic Heating & AC INC | Related taxable corporation/trust | Contractor | OH | 311002682 |
| B&B Mechanical Services Aquis | Related taxable corporation/trust | Contractor | — | — |
| Bachman's INC | Related taxable corporation/trust | Contractor | OH | 310580562 |
| BMWC Constructors INC | Related taxable corporation/trust | Contractor | IN | — |
| Bowen Engineering Corporation | Related taxable corporation/trust | Contractor | IN | — |
| C&D Mechanical INC | Related taxable corporation/trust | Contractor | OH | 311099535 |
| Carrier Commercial Service | Related taxable corporation/trust | Contractor | NY | 060991716 |
| Clay's Performance Construction | Related taxable corporation/trust | Contractor | KY | — |
| Climate PROS | Related taxable corporation/trust | Contractor | — | 550914273 |
| Daikin Applied Americas | Related taxable corporation/trust | Contractor | MN | 410404230 |
| Debra-Kuempel | Related taxable corporation/trust | Contractor | OH | 131615931 |
| Driekast Piping Corporation | Related taxable corporation/trust | Contractor | OH | 311202047 |
| Elitaire LLC | Related taxable corporation/trust | Contractor | — | 853531629 |