| LMLafarge Mid-atlantic, LLC - Jessup Plant | Jessup | MD | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| LCLamotte Company | Chestertown | MD | Chemical Manufacturing325998 | — | ◇ UNVERIFIED |
| LSLaurel Sand and Gravel, INC. - Elkridge | Elkridge | MD | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| LSLaurel Sand & Gravel, INC - Laurel | Laurel | MD | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| LCLebanon Chemical 50 | Baltimore | MD | Chemical Manufacturing325312 | — | ◇ UNVERIFIED |
| LBLegend Brands | Baltimore | MD | Chemical Manufacturing325611 | — | ◇ UNVERIFIED |
| LTLife Technologies | Frederick | MD | Chemical Manufacturing325413 | — | ◇ UNVERIFIED |
 Life Technologies | Frederick | MD | Chemical Manufacturing325413 | — | ◇ UNVERIFIED |
| LTLife Technologies INC | Gaithersburg | MD | Chemical Manufacturing325998 | — | ◇ UNVERIFIED |
| LBLiller Brothers Asphalt | Cumberland | MD | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| LOLorco of Maryland | Elkton | MD | Petroleum and Coal Products Manufacturing324110 | — | ◇ UNVERIFIED |
| LMLynch, Md | Worton | MD | Chemical Manufacturing325312 | — | ◇ UNVERIFIED |
| MEMahoney Environmental Dc | Beltsville | MD | Food Manufacturing311613 | — | ◇ UNVERIFIED |
| MIMarada Industries | Westminster | MD | Transportation Equipment Manufacturing336370 | — | ◇ UNVERIFIED |
| MTMark Trece, INC. | Fallston | MD | Printing and Related Support Activities323122 | — | ◇ UNVERIFIED |
| MMMartin Marietta Laboratories | Halethorpe | MD | Computer and Electronic Product Manufacturing334511 | — | ◇ UNVERIFIED |
| MEMartin's Elevator | Hagerstown | MD | Food Manufacturing311119 | — | ◇ UNVERIFIED |
| MCMaryland Compassionate Care and Wellness | Taneytown | MD | Chemical Manufacturing325411 | — | ◇ UNVERIFIED |
| MCMaryland Concrete Septic Tank INC. | Maryland Line | MD | Nonmetallic Mineral Product Manufacturing327332 | — | ◇ UNVERIFIED |
| MMMaryland Mce Jessup Correctional Institution | Jessup | MD | Furniture and Related Product Manufacturing337127 | — | ◇ UNVERIFIED |
| MPMaryland Paving Churchville | Bel Air | MD | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| MRMaryland Recycling | Baltimore | MD | Primary Metal Manufacturing331314 | — | ◇ UNVERIFIED |
| MMMattern Materials | Boonsboro | MD | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| MCMccormick & CO - 10901 Gilroy Road | Hunt Valley | MD | Food Manufacturing311942 | — | ◇ UNVERIFIED |
| MCMccormick & Company, INC. | Hunt Valley | MD | Food Manufacturing311822 | — | ◇ UNVERIFIED |
| MCMccorquodale Color Card | Whiteford | MD | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| MPMcgregor Printing | Westminster | MD | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| MMelwood | Upper Marlboro | MD | Chemical Manufacturing325320 | — | ◇ UNVERIFIED |
| MAMemtec America CORP. Plant I | Timonium | MD | Machinery Manufacturing333999 | — | ◇ UNVERIFIED |
| MSMerial Select | Berlin | MD | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| MCMid-atlantic Corporation | Silver Spring | MD | Beverage and Tobacco Product Manufacturing312111 | — | ◇ UNVERIFIED |
| MMMonarch Manufacturing, INC. | Belcamp | MD | Plastics and Rubber Products Manufacturing326121 | — | ◇ UNVERIFIED |
| MCMontgomery College - Silver Spring Campus | Silver Spring | MD | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| MMosaic | Cheverly | MD | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| MCMpa - Cox Creek | Baltimore | MD | Primary Metal Manufacturing331000 | — | ◇ UNVERIFIED |
| MLMpi Labels of Baltimore, INC | Baltimore | MD | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| MSMt Savage Firebrick | Frostburg | MD | Nonmetallic Mineral Product Manufacturing327124 | — | ◇ UNVERIFIED |
| MSMt Savage Specialty Refractories | Mount Savage | MD | Nonmetallic Mineral Product Manufacturing327120 | — | ◇ UNVERIFIED |
| NDNevamar Decorative Surfaces Div Odenton Facility | Odenton | MD | Plastics and Rubber Products Manufacturing326130 | — | ◇ UNVERIFIED |
| NCNew Cingular Wireless Pcs, LLC Dba At&t Mobility | Columbia | MD | Miscellaneous Manufacturing339920 | — | ◇ UNVERIFIED |
| NJNew Jersey Fireworks | Elkton | MD | Chemical Manufacturing325998 | — | ◇ UNVERIFIED |
| NMNewstech Md LP | Hagerstown | MD | Paper Manufacturing322100 | — | ◇ UNVERIFIED |
| NNNexagen Networks INC. | Aberdeen | MD | Machinery Manufacturing333415 | — | ◇ UNVERIFIED |
| NGNorthrop Grumman Defense Systems | Middle River | MD | Transportation Equipment Manufacturing336411 | — | ◇ UNVERIFIED |
| NGNorthrop Grumman Sys CORP | Gaithersburg | MD | Computer and Electronic Product Manufacturing334290 | — | ◇ UNVERIFIED |
| NGNorthrop Grumman Systems Corporation | Beltsville | MD | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| NGNorthrop Grumman Systems CORP -troy Hill 4 | Elkridge | MD | Computer and Electronic Product Manufacturing334511 | — | ◇ UNVERIFIED |
| NCNoxell CORP. | Cockeysville | MD | Chemical Manufacturing325620 | — | ◇ UNVERIFIED |
| OCOffray, C.m. & Son, INC. | Hagerstown | MD | Textile Mills313221 | — | ◇ UNVERIFIED |
| OIOnguard Industries LLC | Havre De Grace | MD | Leather and Allied Product Manufacturing316210 | — | ◇ UNVERIFIED |
