| National Railway Equipment Co | Transportation and Warehousing | $6,444,900 | $6,143,852 | 494 | $38.5M |  Research |
| Benoist Brothers Supply Company | Wholesale Trade | $1,542,657 | $1,557,817 | 124 | $38.0M | Research |
| Tri-County Electrical Co-Op, INC | Utilities | $1,218,100 | $1,230,848 | 49 | N/A | Research |
| Spero Family Services | Health Care and Social Assistance | $1,097,800 | $1,112,508 | 148 | N/A | Research |
| Othopedic Center of Southern Illinois | Health Care and Social Assistance | $1,025,000 | $1,030,953 | 92 | $28.9M | Research |
| H.b. Williamson | Wholesale Trade | $923,505 | $926,840 | 58 | $17.8M | Research |
| H.b. Williamson Co. | Wholesale Trade | $917,400 | $926,166 | 81 | $24.8M | Research |
| Bennett Metal Products Inc. | Manufacturing | $913,478 | $918,609 | 47 | $11.5M | Research |
| Bennett Metal Products, Inc. | Manufacturing | $913,400 | $923,360 | 53 | $13.9M | Research |
| Magnum Steel Works, INC | Manufacturing | $886,500 | $894,661 | 87 | $22.8M | Research |
| Magnum Steel Works Inc. | Manufacturing | $694,873 | $698,299 | 50 | $14.0M | Research |
| Jefferson County Comprehensive Services INC | Health Care and Social Assistance | $680,507 | $686,783 | 73 | N/A | Research |
| Krehbiel & Associates | Professional, Scientific, and Technical Services | $562,887 | $568,300 | 32 | $10.2M | Research |
| Asbery and Associates Ob Gyn LLC | Health Care and Social Assistance | $512,100 | $515,912 | 36 | $11.3M | Research |
| Karco, Inc. | Retail Trade | $479,067 | $483,451 | 80 | $12.2M | Research |
| Nutherm International, INC | Manufacturing | $442,200 | $444,608 | 27 | $7.1M | Research |
| Ardl, Inc. | Professional, Scientific, and Technical Services | $425,000 | $427,633 | 40 | <$5M | Research |
| Donoho Insurance Agency, Inc. | Finance and Insurance | $403,200 | $405,854 | 31 | $15.9M | Research |
| Phoenix Modular Elevator, Inc. | Manufacturing | $397,100 | $399,328 | 37 | $9.7M | Research |
| Jefferson County Comprehensive Services, INC | Public Administration | $393,200 | $395,799 | 72 | N/A | Research |
| Sci Box LLC | Manufacturing | $389,959 | $392,737 | 31 | $30.7M | Research |
| Sci Box LLC | Manufacturing | $389,959 | $392,203 | 30 | $29.8M | Research |
| Shamrock Services LLC | Health Care and Social Assistance | $387,500 | $479,242 | 50 | $8.5M | Research |
| Schmidt Chevrolet of Mt. Vernon Inc. | Retail Trade | $380,960 | $383,729 | 30 | $7.6M | Research |
| Lay's Mining Service INC | Other Services (except Public Administration) | $375,064 | $376,429 | 34 | $7.3M | Research |