| IEInnovative Engineered Solutions | Wilmington | OH | 20–99 | ◐ LIKELY ACTIVE |
| IDInrock Drilling Systems | Houston | TX | 20–99 | ◐ LIKELY ACTIVE |
| IFIntegral Fabrication & Engineering, LLC | Orlando | FL | — | ◐ LIKELY ACTIVE |
| IMIntegrated Machining CO | Albuquerque | NM | — | ◐ LIKELY ACTIVE |
| IMIntegrated Machining Solutions INC | Norwalk | CA | — | ◐ 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 |
| IVIntellectual Ventures Property Holdings LLC | Bellevue | WA | — | ◐ LIKELY ACTIVE |
| ISIntellifab Solutions LLC | Atlanta | GA | — | ◐ LIKELY ACTIVE |
| IMInter-city Manufacturing, INC. | Seaside | CA | — | ◐ LIKELY ACTIVE |
| IMInterior Mobile Welding & Services INC | Fairbanks | AK | — | ◐ LIKELY ACTIVE |
International Computer Appliances Corporation | Minneapolis | MN | 100–499 | ◐ LIKELY ACTIVE |
| IQInternational Quality Advantage LLC | Windsor Mill | MD | — | ◐ LIKELY ACTIVE |
International Tool and Manufacturing, INC | Fairfield | NJ | — | ◐ LIKELY ACTIVE |
| ICInvicta Contracting LLC | Osburn | ID | — | ◐ LIKELY ACTIVE |
| IGIra G Steffy & Son, Inc. | Ephrata | PA | 100–499 | ◐ LIKELY ACTIVE |
| IDir Distributers D. B. A. The Metal Shop | Dunnellon | FL | 20–99 | ◐ LIKELY ACTIVE |
| ISIron Sharpens Iron Welding & Fabricating, INC | Minneola | FL | — | ◐ LIKELY ACTIVE |
| ISIrwin Steel LLC | Justin | TX | 100–499 | ◐ LIKELY ACTIVE |
| IDIsidore DBA Twin Oaks Manufacturing | San Jose | CA | 1–19 | ◐ LIKELY ACTIVE |
| IMIsland Machine, INC | Everett | WA | — | ◐ 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 |
| IBITW Building Components Group Inc - Orlando | Orlando | FL | 1–19 | ◐ LIKELY ACTIVE |
| IBITW Building Components Group Inc - Pontotoc, MS | Pontotoc | MS | 20–99 | ◐ LIKELY ACTIVE |
| IBITW Building Components Group Inc - Sacramento, CA | Sacramento | CA | 1–19 | ◐ LIKELY ACTIVE |
| IHITW Heartland - Manufactured Products | Alexandria | MN | 20–99 | ◐ LIKELY ACTIVE |
| IJIvan Jukic & Jure Jukic Partners | Milford | CT | — | ◐ LIKELY ACTIVE |
| INIVI North, Inc. | Greenville | WI | 100–499 | ◐ LIKELY ACTIVE |
| INIVI North, Inc. - OK Branch | Muskogee | OK | 1–19 | ◐ LIKELY ACTIVE |
| ISIVI South, Inc. | Inman | SC | 20–99 | ◐ LIKELY ACTIVE |
| JEJ5 Enterprises, LLC | Moscow Mills | MO | — | ◐ LIKELY ACTIVE |
| JLJabil Lewis Engineering | Grand Junction | CO | 20–99 | ◐ LIKELY ACTIVE |
| JJackson-Cook | Tallahassee | FL | 20–99 | ◐ LIKELY ACTIVE |
| JFJackson Field Welding Services, INC. | Tenino | WA | — | ◐ LIKELY ACTIVE |
| JJacksonville | Jacksonville | TX | 100–499 | ◐ LIKELY ACTIVE |
| JAJacobs Acquisition CO LLC | Hanover | PA | — | ◐ LIKELY ACTIVE |
| JPJacobs Precision Welding, INC | Lead | SD | — | ◐ LIKELY ACTIVE |
| JMJaco Machine LLC | Amory | MS | — | ◐ LIKELY ACTIVE |
| JLJadeforge LLC | Gainesville | FL | — | ◐ LIKELY ACTIVE |
| JTJaeckel Tool and Manufacturing, INC | Athens | TX | — | ▲ REPORTED CLOSED |
| JMJah Machine INC. | Brea | CA | — | ◐ LIKELY ACTIVE |
| JRJame Roll Form Products, LLC | Franklin Park | IL | 100–499 | ◐ LIKELY ACTIVE |
| JBJames B. Maxwell | Grandview | MO | — | ◐ LIKELY ACTIVE |