| LSLigonier Stone & Lime Concrete | Latrobe | PA | 1–19 | ◐ LIKELY ACTIVE |
| LCLincoln CO Ready Mix INC | Stanford | KY | — | ◐ LIKELY ACTIVE |
| LRLincoln Ready-mix Concrete | Lincoln | MO | — | ◐ LIKELY ACTIVE |
| LPLindsay Precast INC. | Franklinton | NC | 20–99 | ◐ LIKELY ACTIVE |
| LPLindsay Precast SC | Rock Hill | SC | 20–99 | ◐ LIKELY ACTIVE |
| LSLithia Springs Plant 210 | Lithia Springs | GA | 20–99 | ◐ LIKELY ACTIVE |
| LOLive Oak Ready Mix, LLC | Ingleside | TX | 20–99 | ◐ LIKELY ACTIVE |
| LALombard Architectural Precast Products Company | Alsip | IL | 20–99 | ◐ LIKELY ACTIVE |
| LWLone Wolf Enterprises-harrisonville | Harrisonville | MO | — | ◐ LIKELY ACTIVE |
| LRLoughman Ready Mix Plant, Maschmeyer Concrete | Davenport | FL | — | ◐ LIKELY ACTIVE |
| LPLowe Precast, INC. | Waco | TX | — | ◐ LIKELY ACTIVE |
| LCL.s. Construction Services (was Licausi) | Independence | MO | — | ◐ LIKELY ACTIVE |
| LILycon INC | Janesville | WI | 100–499 | ◐ LIKELY ACTIVE |
| LRLynchburg Ready-mix Concrete CO INC | Lynchburg | VA | — | ◐ LIKELY ACTIVE |
| LRLynchburg Ready Mix Concrete CO INC - Appomattox | Appomattox | VA | — | ◐ LIKELY ACTIVE |
| MCMabank Cbp No 1 | Mabank | TX | — | ◐ LIKELY ACTIVE |
Mack Industries of Bluffton | Bluffton | OH | 1–19 | ◐ LIKELY ACTIVE |
| MCMajor Concrete 2 New Kings Road Facility | Jacksonville | FL | — | ◐ LIKELY ACTIVE |
| MCMarion CO Concrete | Lebanon | KY | — | ◐ LIKELY ACTIVE |
| MPMaryland Portable Concrete Elkton | Elkton | MD | 20–99 | ◐ LIKELY ACTIVE |
| MPMaryland Portable Concrete, INC. | Havre De Grace | MD | — | ◐ LIKELY ACTIVE |
| MCMaschmeyer Concrete/brooks Street Facility | Lakeland | FL | — | ◐ LIKELY ACTIVE |
| MCMaschmeyer Concrete-hickory Tree Rd | Saint Cloud | FL | — | ◐ LIKELY ACTIVE |
| MCMaschmeyer Concrete Rocket Blvd Facility | Orlando | FL | — | ◐ LIKELY ACTIVE |
| MMMaster Made Tanks, Inc. | Paris | AR | 20–99 | ◐ LIKELY ACTIVE |
| MCMechanicsville Concrete Llc-petersburg Plant | Petersburg | VA | — | ◐ LIKELY ACTIVE |
| MMMemorial Monuments Meridian | Meridian | ID | 20–99 | ◐ LIKELY ACTIVE |
| MCMesquite Concrete Cuero | Cuero | TX | 1–19 | ◐ LIKELY ACTIVE |
| MMMetromont Materials Corporation - Monroe Plant | Monroe | NC | — | ◐ LIKELY ACTIVE |
| MRMetro Ready Mix Concrete INC. | Nashville | TN | — | ◐ LIKELY ACTIVE |
| MRMetro Ready Mix & Supply Castor Ave Fac | Philadelphia | PA | — | ◐ LIKELY ACTIVE |
| MCMeuth Construction Supply | Henderson | KY | — | ◐ LIKELY ACTIVE |
| MCMeuth Construction Supply - Eddyville Plant | Eddyville | KY | — | ◐ LIKELY ACTIVE |
| MCMeuth Construction Supply INC - Morganfield | Morganfield | KY | — | ◐ LIKELY ACTIVE |
| MCMeuth Construction Supply – Owensboro Plant | Owensboro | KY | — | ◐ LIKELY ACTIVE |
| MCMeuth Construction Supply - Sebree Plant | Sebree | KY | — | ◐ LIKELY ACTIVE |
| MMMeyer Material | Mchenry | IL | — | ◐ LIKELY ACTIVE |
Meyer Utility Structures LLC | Fort Pierce | FL | — | ◐ LIKELY ACTIVE |
| MAMid America Ready Mix - Lyons Plant | Lyons | KS | — | ◐ LIKELY ACTIVE |
| MAMid Atlantic Terminals Shutdown | Chesapeake | VA | — | ◐ LIKELY ACTIVE |
| MCMiddlesboro Concrete Plant | Middlesboro | KY | — | ◐ LIKELY ACTIVE |
| MMidland | Midland | TX | 20–99 | ◐ LIKELY ACTIVE |
| MTMidland Tank Farm Crude Oil Storage Facility | Midland | TX | — | ◐ LIKELY ACTIVE |
| MCMid-missouri Concrete | Montgomery City | MO | — | ◐ LIKELY ACTIVE |
| MSMid South Concrete, INC. | Pulaski | TN | — | ◐ LIKELY ACTIVE |
| MSMid - South Concrete, INC. - Leoma | Leoma | TN | — | ◐ LIKELY ACTIVE |
| MSMid State Concrete Products LLC | Santa Maria | CA | 20–99 | ◐ LIKELY ACTIVE |
| MRMid-state Ready Mix | Columbia | KY | — | ◐ LIKELY ACTIVE |
| MCMid-States Concrete Industries | South Beloit | IL | 100–499 | ◐ LIKELY ACTIVE |
| MRMidtown Redi Mix | Westville | IL | — | ◐ LIKELY ACTIVE |
| MMMid-way Materials, INC. | Camden | TN | — | ◐ LIKELY ACTIVE |
| MCMidwest Concrete Materials INC | Salina | KS | — | ◐ LIKELY ACTIVE |
| MMMilpitas Materials Company | Milpitas | CA | 20–99 | ◐ LIKELY ACTIVE |
| MMMini Mix INC | Clinton Twp | MI | 20–99 | ◐ LIKELY ACTIVE |
| MCMitchell Concrete Specialties, LLC | Alabaster | AL | — | ◐ LIKELY ACTIVE |
Mmc Materials Gulf Coast - Milton Plant | Milton | FL | — | ◐ LIKELY ACTIVE |
Mmc Materials Gulf Coast - Panama City Plant | Panama City | FL | — | ◐ LIKELY ACTIVE |
Mmc Materials Gulf Coast - Tyndall Plant | Tyndall Afb | FL | — | ◐ LIKELY ACTIVE |
Mmc Materials, INC. | Luverne | AL | — | ◐ LIKELY ACTIVE |
| MMMmc Materials Inc, Aberdeen Facility | Aberdeen | MS | — | ◐ LIKELY ACTIVE |
Mmc Materials Inc, Byhalia Plnt | Byhalia | MS | — | ◐ LIKELY ACTIVE |
| MMMmc Materials Inc, Columbia | Columbia | MS | — | ◐ LIKELY ACTIVE |
| MMMmc Materials Inc, Columbus 45 | Columbus | MS | — | ◐ LIKELY ACTIVE |
| MMMmc Materials Inc, Mccomb | Mccomb | MS | — | ◐ LIKELY ACTIVE |
| MMMmc Materials Inc, Natchez Plant | Natchez | MS | — | ◐ LIKELY ACTIVE |
| MMMmc Materials, Inc., North Natchez Plant | Natchez | MS | — | ◐ LIKELY ACTIVE |
| MCMoon Concrete Services, INC. | Huntsville | AL | — | ◐ LIKELY ACTIVE |
| MVMoreno Valley Plant 2 | Moreno Valley | CA | 20–99 | ◐ LIKELY ACTIVE |
| MCMorgan Concrete Company - Athens Plant | Athens | GA | 20–99 | ◐ LIKELY ACTIVE |
| MCMoritz Concrete | Effingham | IL | 20–99 | ◐ LIKELY ACTIVE |
| MTMorrison Tank & Vault, INC. | Morrison | TN | — | ◐ LIKELY ACTIVE |
| MCMountain City Plant 506 | Mountain City | TN | — | ◐ LIKELY ACTIVE |
| MEMPC Enterprises Inc | Mount Pleasant | IA | 100–499 | ◐ LIKELY ACTIVE |
| MVMt Vernon Plant | Rockcastle | KY | — | ◐ LIKELY ACTIVE |
| NBNarvick Brothers Lumber CO INC | Minooka | IL | — | ◐ LIKELY ACTIVE |
| NRNashville Ready Mix, INC. | Nashville | TN | — | ◐ LIKELY ACTIVE |
| NRNashville Ready Mix, INC. | Nashville | TN | — | ◐ LIKELY ACTIVE |
| NRNashville Ready Mix, INC. | Nashville | TN | — | ◐ LIKELY ACTIVE |
| NRNashville Ready Mix of Murfreesboro | Murfreesboro | TN | — | ◐ LIKELY ACTIVE |
| NBNational Block Company INC | Westland | MI | — | ◐ LIKELY ACTIVE |
| NCNational City Ready Mix | National City | CA | 20–99 | ◐ LIKELY ACTIVE |
| NINebco INC. Dba Overland Ready Mix Belleville Ks. Plant | Belleville | KS | — | ◐ LIKELY ACTIVE |
| NCNeo Concrete & Materials, INC. | Grove | OK | — | ◐ LIKELY ACTIVE |
| NNewark | Newark | NJ | 100–499 | ◐ LIKELY ACTIVE |
| NBNew Boston Concrete, INC. | New Boston | TX | — | ◐ LIKELY ACTIVE |
| NCNitterhouse Concrete Prod | Chambersburg | PA | — | ◐ LIKELY ACTIVE |
| NNoblesville | Noblesville | IN | 20–99 | ◐ LIKELY ACTIVE |
| NRNorfolk Rmc Facility | Norfolk | VA | — | ◐ LIKELY ACTIVE |
| NSNorfolk Southern Railway | Spartanburg | SC | — | ◐ LIKELY ACTIVE |
| NLNorth Lamar Concrete INC | Sumrall | MS | — | ◐ LIKELY ACTIVE |
| NGNWPX Geneva - Orem | Orem | UT | 100–499 | ◐ LIKELY ACTIVE |
| OROhio River Concrete CORP | Marion | KY | — | ◐ LIKELY ACTIVE |
| OCOk Concrete Company | Wichita Falls | TX | 20–99 | ◐ LIKELY ACTIVE |
| OCOld Castle Apg | Riverhead | NY | — | ◐ LIKELY ACTIVE |
| OAOldcastle Apg South, INC. | Franklin | TN | — | ◐ LIKELY ACTIVE |
| OBOldcastle Building Envelope | Fremont | CA | 100–499 | ◐ LIKELY ACTIVE |
| OCOldcastle Coastal INC | Fort Myers | FL | — | ◐ LIKELY ACTIVE |
| OPOldcastle Precast INC | South Bethlehem | NY | — | ◐ LIKELY ACTIVE |
| OSOldcastle Sw Group - Anderson Rmc | Delta | CO | — | ◐ LIKELY ACTIVE |
| OSOldcastle Sw Group - Rifle Rmc Plant | Rifle | CO | — | ◐ LIKELY ACTIVE |