| Sheet Metal Workers Local Union No 19 Pension Fund | Related tax-exempt org | Pension fund | — | 231494364 |
| Sheet Metal Workers Local Union No 19 SUB Fund | Related tax-exempt org | SUB fund | — | 232681497 |
| Sheet Metal Workers Local Union No 19 Annuity Fund | Related tax-exempt org | Annuity fund | — | 232245696 |
| Sheet Metal Workers Local Union No 19 | Related tax-exempt org | Labor union | — | 231077755 |
| Sheet Metal Workers Joint Apprentice | Related tax-exempt org | Training fund | — | 236428928 |
| Sheet Metal Workers JATC of Central PA | Related tax-exempt org | Training fund | — | 232004118 |
| A a a Sheet Metal INC | Related taxable corporation/trust | — | — | — |
| A C Gentry | Related taxable corporation/trust | — | — | — |
| A D S INC | Related taxable corporation/trust | — | — | — |
| A S L Refrigeration INC | Related taxable corporation/trust | — | — | — |
| A Zahner Company | Related taxable corporation/trust | — | — | — |
| AW Farrell & SON INC | Related taxable corporation/trust | — | — | — |
| ABCO Sign CO | Related taxable corporation/trust | — | — | — |
| ACCU-FLOW Balancing CO LLC | Related taxable corporation/trust | — | — | — |
| Advanced AIR Service Group | Related taxable corporation/trust | — | — | — |
| Advanced Sheet Metal | Related taxable corporation/trust | — | — | — |
| Aella Industries | Related taxable corporation/trust | — | — | — |
| Aerdux Incorporated | Related taxable corporation/trust | — | — | — |
| AIR Balancing Engineers | Related taxable corporation/trust | — | — | — |
| AIR Concepts INC | Related taxable corporation/trust | — | — | — |
| AIR Tight Heating & Cooling | Related taxable corporation/trust | — | — | — |
| AJM Mechanical LLC | Related taxable corporation/trust | — | — | — |
| Allied Power Services LLC | Related taxable corporation/trust | — | — | — |
| American Mechanical & Contract | Related taxable corporation/trust | — | — | — |
| ASC Sheet Metal LLC | Related taxable corporation/trust | — | — | — |