| IRIndustrial Rigging Services of Central Texas | Hewitt | TX | 20–99 | ◐ LIKELY ACTIVE |
| ISIndustrial Steel South LLC | Rockledge | FL | 1–19 | ◐ LIKELY ACTIVE |
| ISIndustrial Stripping Services LLC | Grand Rapids | MI | 20–99 | ◐ LIKELY ACTIVE |
| ITIndustrial Technologies Group ITG CA Design Raleigh | Raleigh | NC | 20–99 | ◐ LIKELY ACTIVE |
| ITIndustrial Technologies Group ITG WakefieldNashua | Nashua | NH | 100–499 | ◐ LIKELY ACTIVE |
| IIndy | Indianapolis | IN | 1–19 | ◐ LIKELY ACTIVE |
| IIIN-FAB Inc. | Bedford | IN | 20–99 | ◐ LIKELY ACTIVE |
| IDInfinity Drain LTD | Amityville | NY | 100–499 | ◐ LIKELY ACTIVE |
| IFInfinity Finishing Services, Inc. | Fort Worth | TX | 1–19 | ◐ LIKELY ACTIVE |
| IFInfrastructure Fabrication LLC | Bath | PA | — | ◐ LIKELY ACTIVE |
| ITInlet Tools, INC | Conneautville | PA | — | ◐ LIKELY ACTIVE |
| IWInnisfallen Works | Springfield | OH | 20–99 | ◐ LIKELY ACTIVE |
| IMInnovations Manufacturing INC | Redding | CA | — | ◐ LIKELY ACTIVE |
| IEInnovative Engineered Solutions | Wilmington | OH | 20–99 | ◐ LIKELY ACTIVE |
| IMInnovative Mechanical Solutions LLC- IMECH | Houston | TX | 20–99 | ◐ LIKELY ACTIVE |
| IDInrock Drilling Systems | Houston | TX | 20–99 | ◐ LIKELY ACTIVE |
| IQInteger, QKP | Quakertown | PA | 100–499 | ◐ LIKELY ACTIVE |
| IMIntegrated Machining CO | Albuquerque | NM | — | ◐ LIKELY ACTIVE |
| IMIntegrated Machining Solutions INC | Norwalk | CA | — | ◐ LIKELY ACTIVE |
| IMIntegrated Manufacturing West Jefferson NC | West Jefferson | NC | 100–499 | ◐ LIKELY ACTIVE |
| IIIntegration INC | Albuquerque | NM | — | ◐ LIKELY ACTIVE |
| IEIntegrity Engineering Holding, Inc | Ramsey | MN | 20–99 | ◐ LIKELY ACTIVE |
| IMIntegrity Machining, INC | Augusta | IL | — | ◐ LIKELY ACTIVE |
| IMIntegrity Manufacturing CORP | Dayton | OH | — | ◐ LIKELY ACTIVE |
| IVIntellectual Ventures Property Holdings LLC | Bellevue | WA | — | ◐ LIKELY ACTIVE |
| ICIntelligent Composites LLC | Milwaukee | WI | — | ◐ LIKELY ACTIVE |
| IMInter-city Manufacturing, INC. | Seaside | CA | — | ◐ LIKELY ACTIVE |
| IMInterconnection Marketing ,inc. | Canoga Park | CA | — | ◐ LIKELY ACTIVE |
| IMInterior Mobile Welding & Services INC | Fairbanks | AK | — | ◐ LIKELY ACTIVE |
| IDInternational Destination Trading LLC | Fort Lauderdale | FL | — | ◐ LIKELY ACTIVE |
| IQInternational Quality Advantage LLC | Windsor Mill | MD | — | ◐ LIKELY ACTIVE |
International Tool and Manufacturing, INC | Fairfield | NJ | — | ◐ LIKELY ACTIVE |
| IEIowa Engineered Procsses | Independence | IA | 20–99 | ◐ LIKELY ACTIVE |
| IGIPS Group, Inc Headquarters | San Diego | CA | 100–499 | ◐ LIKELY ACTIVE |
| IGIra G Steffy & Son, Inc. | Ephrata | PA | 100–499 | ◐ LIKELY ACTIVE |
| IEIron Empire LLC | Surprise | AZ | — | ◐ LIKELY ACTIVE |
| ISIron Sharpens Iron Welding & Fabricating, INC | Minneola | FL | — | ◐ LIKELY ACTIVE |
| ISIrwin Steel LLC | Justin | TX | 100–499 | ◐ LIKELY ACTIVE |
| IYISC - Youngstown, OH | Youngstown | OH | 100–499 | ◐ LIKELY ACTIVE |
| IHIsland Hose & Seals, INC. | Deer Park | NY | — | ◐ LIKELY ACTIVE |
| IIIsland Instrument CORP. | Deer Park | NY | — | ◐ LIKELY ACTIVE |
| IMIsland Machine, INC | Everett | WA | — | ◐ LIKELY ACTIVE |
| IPI.S. Parts International, Inc. dba Lattimer | Vineland | NJ | 20–99 | ◐ LIKELY ACTIVE |
| ILIstanbul Logistics Aluminum Trading LLC | Vienna | VA | — | ◐ LIKELY ACTIVE |
| ICItech Custom Manufacturing and Design INC. | Riviera Beach | FL | — | ◐ LIKELY ACTIVE |
| IBITW Building Components Group Inc - Earth City, MO | Earth City | MO | 1–19 | ◐ LIKELY ACTIVE |
| IBITW Building Components Group Inc - Ft. Lauderdale | Fort Lauderdale | FL | 20–99 | ◐ LIKELY ACTIVE |
| IBITW Building Components Group Inc - Glenview, IL | Glenview | IL | 500+ | ◐ LIKELY ACTIVE |
| IBITW Building Components Group Inc - Grand Prairie, TX | Grand Prairie | TX | 20–99 | ◐ LIKELY ACTIVE |
| IBITW Building Components Group Inc - Litchfield | Litchfield | IL | 20–99 | ◐ LIKELY ACTIVE |