| 5143 | Lumber yard | |
| 2010 | Lumber, dimension, made by resawing purchased lumber | |
| 2010 | Lumber, hardwood dimension (e.g., 2x4), made from logs or bolts | |
| 2010 | Lumber, hardwood dimension, made by resawing purchased lumber | |
| 2010 | Lumber, kiln drying | |
| 2022 | Lumber, parallel strand, manufacturing | |
| 5110 | Lumber, plywood and millwork, wholesale agents and brokers | |
| 5143 | Lumber, rough or dressed, wholesale | |
| 2010 | Lumber, softwood dimension (e.g., 2x4), made from logs or bolts | |
| 2010 | Lumber, treating with creosote or other preservatives | |
| 0200 | Lumbering (logging) | |
| 3150 | Lumiline fixtures, manufacturing | |
| 3150 | Luminous panel ceilings, manufacturing | |
| 3110 | Luminous tube transformers, manufacturing | |
| 5520 | Lunch bar | |
| 2899 | Lunch boxes, light gauge metal, manufacturing | |
| 5520 | Lunch room | |
| 5520 | Lunch wagon | |
| 1511 | Luncheon meat (except poultry), made from purchased meat | |
| 1511 | Luncheon meat (except poultry), produced in slaughtering plants | |
| 1511 | Luncheon meat, poultry, manufacturing | |
| 5520 | Luncheonette | |
| 3610 | Lunchroom fixtures (except wood), manufacturing | |
| 3610 | Lunchroom fixtures, metal, manufacturing | |
| 3610 | Lunchroom fixtures, wood, manufacturing | |
| 5520 | Lunchrooms | |
| 9191 | Lutheran church | |
| 2022 | LVL (laminated veneer lumber), manufacturing | |
| 2411 | Lye, household type, manufacturing | |