| Thorlabs Inc. CO | Manufacturing | 0 | — | A |
| Thorlabs Inc. NY | Manufacturing | 0 | — | A |
| Thorlabs Inc. SC | Manufacturing | 0 | — | A |
| Thorlabs Quantum Electronics, Inc MD | Manufacturing | 0 | — | A |
| Thorlabs, Inc VA | Manufacturing | 0 | — | D |
| Thorlabs, Inc. MI | Manufacturing | 0 | — | A |
| Thorlabs, Inc. NJ | Manufacturing | 1 | $129,215 | D |
| Thorley Industries LLC PA | — | 0 | — | — |
| Thorlund Brothers MI | Agriculture & Forestry | 0 | — | D |
| Thorn Creek Basin Sanitary District IL | Utilities | 0 | — | F |
| Thornapple Excavating, Inc. MI | Construction | 0 | — | A |
| Thornburg Investment Management, Inc. NM | Finance & Insurance | 1 | $150,000 | — |
| Thornbury Inc PA | Construction | 0 | — | F |
| Thorne ID | — | 0 | — | — |
| Thorne Associates, Inc IL | Construction | 0 | — | C |
| Thorne Electric, Inc. IL | Construction | 0 | — | F |
| Thorne Research SC | Manufacturing | 0 | — | D |
| Thorne's Excavating Co., LLC TN | Construction | 0 | — | F |
| Thorneburg Hosiery NC | Manufacturing | 0 | — | A |
| Thorneburg Hosiery Mills NC | Manufacturing | 0 | — | A |
| Thornfield Hall, Inc CT | Healthcare & Social Assistance | 0 | — | F |
| Thornton and Grooms MI | Construction | 0 | — | F |
| Thornton Carpet Inc SD | Retail Trade | 0 | — | B |
| Thornton Construction Company, Inc FL | Construction | 2 | $77,730 | A |
| Thornton Heating & Sheetmetal ID | Construction | 0 | — | F |
| Thornton Heights Terrace IL | Healthcare & Social Assistance | 0 | — | F |
| Thornton Industries PA | Manufacturing | 0 | — | A |
| THORNTON PLACE KS | Healthcare & Social Assistance | 0 | — | A |
| Thornton Steel Company, LLC TX | Manufacturing | 0 | — | F |
| Thornton Steel San Antonio, LLC TX | Manufacturing | 0 | — | F |
| Thornton Tomasetti, Inc. NY | Professional & Technical Services | 22 | $101,548 | — |
| Thorntons Plumbing Inc NC | Construction | 0 | — | D |
| THORNTREE COUNTRY CLUB TX | Arts & Entertainment | 0 | — | A |
| Thoro Packaging CA | Manufacturing | 0 | — | F |
| Thorough Built LLC TN | Manufacturing | 0 | — | F |
| Thoroughbred Contractors LLC KY | Construction | 0 | — | D |
| Thoroughbred Fulfillment LLC MI | Transportation & Warehousing | 0 | — | B |
| Thoroughfare Logistics LLC CA | Transportation & Warehousing | 0 | — | F |
| THOROUGHFARE MINING LLC KY | — | 0 | — | — |
| Thorp Equipment Inc WI | Manufacturing | 0 | — | A |
| Thorpe Design Inc CA | Construction | 0 | — | F |
| Thorpe Specialty Services Corporation TX | Construction | 0 | — | A |
| Thors Elegance Inc. VT | Manufacturing | 0 | — | F |
| Thorsby Engineered Wood Products AL | — | 0 | — | — |
| Thorsen's Greenhouse OH | Agriculture & Forestry | 0 | — | A |
| THORSEN'S-NORQUIST, INC. CA | Construction | 0 | — | F |
| Thorstad Companies MN | Construction | 0 | — | A |
| Thorstad Construction Co. Inc MN | Construction | 0 | — | A |
| THORTEX OR | Manufacturing | 0 | — | B |
| THORUD INC MN | Manufacturing | 0 | — | C |
