| MDMaster Dowel | Ankeny | IA | Plastics and Rubber Products Manufacturing326121 | — | ◇ UNVERIFIED |
| MCMax Cast | Kalona | IA | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| MLMaytag - Laundry Products - Plant 1 | Newton | IA | Electrical Equipment, Appliance & Component Manufacturing335220 | — | ◇ UNVERIFIED |
| MNMaytag - Newton Laundry Products - Plant 2 | Newton | IA | Electrical Equipment, Appliance & Component Manufacturing335220 | — | ◇ UNVERIFIED |
| MAMcgill Airflow LLC | Grinnell | IA | Fabricated Metal Product Manufacturing332322 | — | ◇ UNVERIFIED |
| MBMckee Button Company | Muscatine | IA | Miscellaneous Manufacturing339993 | — | ◇ UNVERIFIED |
| MMepco | Marshalltown | IA | Primary Metal Manufacturing331528 | — | ◇ UNVERIFIED |
| MCMeredith Corporation | Des Moines | IA | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| MMMfi Merchandising | Winterset | IA | Fabricated Metal Product Manufacturing332311 | — | ◇ UNVERIFIED |
| MHM H Eby INC | Story City | IA | Machinery Manufacturing333111 | — | ◇ UNVERIFIED |
| MCMi Conveyance Solutions Group-apache Division-ia38 | Cedar Rapids | IA | Plastics and Rubber Products Manufacturing326220 | — | ◇ UNVERIFIED |
| MFMidland Forge Div | Cedar Rapids | IA | Fabricated Metal Product Manufacturing332111 | — | ◇ UNVERIFIED |
| MMMidland Manufacturing Company, INC. | Monroe | IA | Plastics and Rubber Products Manufacturing326199 | 20-99 | ◇ UNVERIFIED |
| MMMidstate Machine | Des Moines | IA | Machinery Manufacturing333512 | — | ◇ UNVERIFIED |
| MBMidwestern Bioag Holdings LLC | Davenport | IA | Nonmetallic Mineral Product Manufacturing327991 | — | ◇ UNVERIFIED |
 Mills Manufacturing INC | Earlville | IA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| MCMinsa Corporation | Red Oak | IA | Food Manufacturing311211 | — | ◇ UNVERIFIED |
| MVMissouri Valley Steel Company | Sioux City | IA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| MMModine Mfg CO - Former Site of | Washington | IA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| MMMonarch Manufacturing CO | Adel | IA | Plastics and Rubber Products Manufacturing326121 | — | ◇ UNVERIFIED |
| MMMonarch Mfg CO | Adel | IA | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| MMMontezuma Manufacturing | Montezuma | IA | Transportation Equipment Manufacturing336370 | — | ◇ UNVERIFIED |
| MRMoorhouse Ready Mix Inc-carroll | Carroll | IA | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| MPMulti Packaging and Printing INC | Newton | IA | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| MMMusco Mobile Lighting | Oskaloosa | IA | Electrical Equipment, Appliance & Component Manufacturing335129 | — | ◇ UNVERIFIED |
| NPNational Purity LLC | Britt | IA | Chemical Manufacturing325611 | — | ◇ UNVERIFIED |
| NUNestle USA | Waverly | IA | Food Manufacturing311320 | — | ◇ UNVERIFIED |
| NNN & N Trailer Sales INC | Monticello | IA | Transportation Equipment Manufacturing336212 | — | ◇ UNVERIFIED |
| NANorris Asphalt Paving Co-plant 450 | Harvey | IA | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| NENorthern Engraving CORP | Waukon | IA | Fabricated Metal Product Manufacturing332116 | — | ◇ UNVERIFIED |
| NGNorthern Gravel CO | Muscatine | IA | Plastics and Rubber Products Manufacturing326211 | — | ◇ UNVERIFIED |
| NPNorthstar Power, LLC | Ankeny | IA | Machinery Manufacturing333618 | — | ◇ UNVERIFIED |
| NINorwalk Iowa Ready Mix | Ankeny | IA | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| NRNorwalk Ready Mix | Des Moines | IA | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| NRNorwalk Ready Mix | Grimes | IA | Machinery Manufacturing333120 | — | ◇ UNVERIFIED |
| NANovartis Animal Health US INC | Larchwood | IA | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| NPNsk-aks Precision Ball Company | Clarinda | IA | Fabricated Metal Product Manufacturing332991 | — | ◇ UNVERIFIED |
| OSOmaha Standard INC | Council Bluffs | IA | Transportation Equipment Manufacturing336211 | — | ◇ UNVERIFIED |
| OMOmg Midwest INC | Johnston | IA | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| OCOrbis Corporation | Manchester | IA | Plastics and Rubber Products Manufacturing326199 | — | ◇ UNVERIFIED |
| PCPackaging CORP of America-marshalltown | Marshalltown | IA | Paper Manufacturing322211 | — | ◇ UNVERIFIED |
| PIPaint-line INC | Fairfield | IA | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| PNPcs Nitrogen Fertilizer - Clinton Plant | Camanche | IA | Chemical Manufacturing325311 | — | ◇ UNVERIFIED |
| PPPdm Precast | Carlisle | IA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| PCPella Corp-carroll Div | Carroll | IA | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| PCPella Corporation | Shenandoah | IA | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| PCPella Corporation - Story City Division | Story City | IA | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| PCPella Corp-shenandoah Div | Shenandoah | IA | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| PFPella Feed Service INC | Pella | IA | Food Manufacturing311119 | — | ◇ UNVERIFIED |
| PCPepsi Cola General Bottlers | Des Moines | IA | Beverage and Tobacco Product Manufacturing312111 | — | ◇ UNVERIFIED |
