| MPMagnetic Power Systems Inc-manufacturers Drive | Fenton | MO | Electrical Equipment, Appliance & Component Manufacturing335314 | — | ◇ UNVERIFIED |
| MLMagnet LLC Innovations | Washington | MO | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| MLMagnet LLC Innovations | Washington | MO | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| MLMagruder Limestone Company Ashely Quarry | Bowling Green | MO | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| MPMagruder Paving LLC (port-0667) | Portable | MO | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| MEMahle Engine Components USA Inc-manchester | Manchester | MO | Transportation Equipment Manufacturing336310 | — | ◇ UNVERIFIED |
| MCMaiman Company (the)-springfield | Springfield | MO | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| MMMallinckrodt Medical INC - St. Louis | Hazelwood | MO | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| MIMammoth INC | Springfield | MO | Fabricated Metal Product Manufacturing332117 | — | ◇ UNVERIFIED |
| MAM and M Country Butchering | Middletown | MO | Food Manufacturing311611 | — | ◇ UNVERIFIED |
| MLMansfield Lime & Stone Quarry INC. | Mountain Grove | MO | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| MTMapp Technologies, L.l.c. | Joplin | MO | Fabricated Metal Product Manufacturing332999 | — | ◇ UNVERIFIED |
| MBMar Bal INC | Cuba | MO | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| MDMarble Dcor INC | Union | MO | Plastics and Rubber Products Manufacturing326191 | — | ◇ UNVERIFIED |
| MCMarchem Cfi | New Haven | MO | Textile Mills313311 | — | ◇ UNVERIFIED |
| MIMarck Industries of Southwest Missouri | Republic | MO | Textile Mills313320 | — | ◇ UNVERIFIED |
| MEMarine Electrical Products | Lebanon | MO | Plastics and Rubber Products Manufacturing326199 | — | ◇ UNVERIFIED |
| MTMark Twain Redi-mix INC. | Bloomsdale | MO | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| MIMarlen International INC | Riverside | MO | Machinery Manufacturing333241 | — | ◇ UNVERIFIED |
| MMMarmic Metal Treating | Saint Charles | MO | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| MTMarquette Tool & Die | St. Louis | MO | Fabricated Metal Product Manufacturing332119 | — | ◇ UNVERIFIED |
| MPMarshall Paving Inc-marshall Paving INC | Marshall | MO | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| MMMarshfield Mill | Marshfield | MO | Food Manufacturing311119 | — | ◇ UNVERIFIED |
| MLMartin Logging & Sawmill | Cherryville | MO | Wood Product Manufacturing321113 | — | ◇ UNVERIFIED |
| MMMaster Made Paints Incorporated | Carl Junction | MO | Chemical Manufacturing325510 | — | ◇ UNVERIFIED |
| MIMastertaste INC | Greenville | MO | Apparel Manufacturing315999 | — | ◇ UNVERIFIED |
| MIMastertaste INC. | Fenton | MO | Food Manufacturing311930 | — | ◇ UNVERIFIED |
| MPMast Pastured Poultry | Jamesport | MO | Food Manufacturing311611 | — | ◇ UNVERIFIED |
| MTMast Technology | Independence | MO | Fabricated Metal Product Manufacturing332992 | — | ◇ UNVERIFIED |
| MPMaterials Packaging CORP | Kansas City | MO | Nonmetallic Mineral Product Manufacturing327000 | — | ◇ UNVERIFIED |
| MUMauser USA LLC CORP - National Container Group | Chillicothe | MO | Printing and Related Support Activities323113 | — | ◇ UNVERIFIED |
| MPMaywood Printing Company | Independence | MO | Printing and Related Support Activities323110 | 1-19 | ◇ UNVERIFIED |
| MTMccay Tool & Engineering Company | Fenton | MO | Transportation Equipment Manufacturing336413 | — | ◇ UNVERIFIED |
| MFMcclain Forest Products LLC | Van Buren | MO | Wood Product Manufacturing321114 | — | ◇ UNVERIFIED |
| MMMc Materials 62 - Mountain View | Mountain View | MO | Chemical Manufacturing325191 | — | ◇ UNVERIFIED |
| MMMc Materials Plant 63 - Summersville | Summersville | MO | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| MMMc Materials Plant 64 - Winona | Winona | MO | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| MUMedrano USA INC | St. Louis | MO | Wood Product Manufacturing321920 | — | ◇ UNVERIFIED |
| MLMemc Llc-st. Peters Plant | St Peters | MO | Computer and Electronic Product Manufacturing334413 | — | ◇ UNVERIFIED |
| MLMerial Limited | St Louis | MO | Chemical Manufacturing325411 | — | ◇ UNVERIFIED |
| MMMeridian Medical Technologies INC | Saint Louis | MO | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| MSMerit Specialities-merit Specialities | St. Louis | MO | Fabricated Metal Product Manufacturing332710 | — | ◇ UNVERIFIED |
 Metal Culverts INC M & M Highway Materials Div | Columbia | MO | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| MRMetal Recovery Sys INC | Saint Louis | MO | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| MMMetro Materials Concrete Batch Plant | Valley Park | MO | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| MMMetro Materials - Hanley Plant-kinloch | Kinloch | MO | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| MMMetro Materials (valley Park Plant)-fenton Supply Company | Valley Park | MO | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| MOMetso Outotec USA INC | Warrenton | MO | Primary Metal Manufacturing331513 | — | ◇ UNVERIFIED |
| MAMfa Agri Service | Bernie | MO | Chemical Manufacturing325314 | — | ◇ UNVERIFIED |
| MAMfa Agri Service | Alma | MO | Food Manufacturing311119 | — | ◇ UNVERIFIED |
