| MVMcavoy Vitrified Brick CO | Phoenixville | PA | Nonmetallic Mineral Product Manufacturing327120 | — | ◐ LIKELY ACTIVE |
Mcdal Corporation | King of Prussia | PA | Machinery Manufacturing333923 | — | ◐ LIKELY ACTIVE |
| MIMcgregor Ind Inc/dunmore Plt | Dunmore | PA | Fabricated Metal Product Manufacturing332312 | 1-19 | ◐ LIKELY ACTIVE |
Meadville Tool Grinding, INC | Conneaut Lake | PA | Machinery Manufacturing333248 | 1-19 | ◐ LIKELY ACTIVE |
| MSMenarini Silicon Biosystems INC | Huntingdon Valley | PA | Chemical Manufacturing325413 | — | ◐ LIKELY ACTIVE |
| MPMenasha Packaging CO LLC | Newville | PA | Paper Manufacturing322211 | — | ◐ LIKELY ACTIVE |
| MUMersen Usa/st Marys | Saint Marys | PA | Nonmetallic Mineral Product Manufacturing327215 | — | ◐ LIKELY ACTIVE |
| MMetaltech/pgh | Pittsburgh | PA | Fabricated Metal Product Manufacturing332812 | — | ◐ LIKELY ACTIVE |
| MPMia Products | Moosic | PA | Food Manufacturing311520 | 100-499 | ◐ LIKELY ACTIVE |
| MIMicro-coax INC | Pottstown | PA | Textile Mills313110 | — | ◐ LIKELY ACTIVE |
| MTMiles T. Weaber & Son, INC | Lebanon | PA | Fabricated Metal Product Manufacturing332323 | 1-19 | ◐ LIKELY ACTIVE |
Mission First Tactical, LLC | Horsham | PA | Fabricated Metal Product Manufacturing332994 | 20-99 | ◐ LIKELY ACTIVE |
| MWMitre Wright Inc. | York | PA | Furniture and Related Product Manufacturing337212 | 20-99 | ◐ LIKELY ACTIVE |
| MDM&M Displays, Inc | Philadelphia | PA | Printing and Related Support Activities323111 | 20-99 | ◐ LIKELY ACTIVE |
| MMMm Metals USA LLC | Fairless Hills | PA | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| MFMolded Fiber Glass CO / Tray Company | Linesville | PA | Plastics and Rubber Products Manufacturing326199 | 100-499 | ◐ LIKELY ACTIVE |
| MFMolded Fiber Glass Co/union City | Union City | PA | Plastics and Rubber Products Manufacturing326121 | — | ◐ LIKELY ACTIVE |
| MTMontgomery Truss & Panel -MAIN | Grove City | PA | Wood Product Manufacturing321214 | 20-99 | ◐ LIKELY ACTIVE |
| MSMontour Steam Electric Station | Washingtonville | PA | Petroleum and Coal Products Manufacturing324199 | — | ◐ LIKELY ACTIVE |
| MTMorgantown Tech Svc/perry Twp Plt | Mount Morris | PA | Machinery Manufacturing333131 | — | ◐ LIKELY ACTIVE |
| MEMorrisville Esg - Electronics Facility | Morrisville | PA | Chemical Manufacturing325120 | — | ◐ LIKELY ACTIVE |
| MIMott's Inc.- Aspers Facility | Aspers | PA | Food Manufacturing311421 | — | ◐ LIKELY ACTIVE |
| MRMountain Ridge Metals Inc/millersburg | Millersburg | PA | Plastics and Rubber Products Manufacturing326121 | — | ◐ LIKELY ACTIVE |
| MJMount Joy Wire Corporation | Mount Joy | PA | Primary Metal Manufacturing331222 | 100-499 | ◐ LIKELY ACTIVE |
| MJMt Joy Wire Corp/mt Joy | Mount Joy | PA | Textile Mills313241 | — | ◐ LIKELY ACTIVE |
| MSMt Savage Specialty Refractories - Ingomar | Ingomar | PA | Nonmetallic Mineral Product Manufacturing327120 | 1-19 | ◐ LIKELY ACTIVE |
| MCMulti Chem Group LLC Washington Facility | Washington | PA | Machinery Manufacturing333318 | — | ◐ LIKELY ACTIVE |
| MFMulti Flex Plating Co/collingdale | Collingdale | PA | Primary Metal Manufacturing331410 | 1-19 | ◐ LIKELY ACTIVE |
| NANcc Automated Systems, INC. | Souderton | PA | Fabricated Metal Product Manufacturing332710 | 20-99 | ◐ LIKELY ACTIVE |
| NPNestle Purina Petcare | Mechanicsburg | PA | Food Manufacturing311111 | — | ◐ LIKELY ACTIVE |
| NPNestle Purina Petcare CO | Allentown | PA | Food Manufacturing311111 | — | ◐ LIKELY ACTIVE |
| NTNetshape Technologies - Falls Creek Facility | Falls Creek | PA | Fabricated Metal Product Manufacturing332117 | — | ◐ LIKELY ACTIVE |
| NPNew Pig CORP | Tipton | PA | Chemical Manufacturing325211 | 500+ | ◐ LIKELY ACTIVE |
| NSN.F. String & Son Inc. | Harrisburg | PA | Paper Manufacturing322230 | 20-99 | ◐ LIKELY ACTIVE |
| NFNissin Foods USA Co/hempfield | Lancaster | PA | Food Manufacturing311423 | 500+ | ◐ LIKELY ACTIVE |
| NPNittany Paper Mills, INC. | Lewistown | PA | Paper Manufacturing322121 | 100-499 | ◐ LIKELY ACTIVE |
| NCNitterhouse Concrete Products | Chambersburg | PA | Nonmetallic Mineral Product Manufacturing327390 | 20-99 | ◐ LIKELY ACTIVE |
| NMNNBC - Maugus Manufacturing | Lancaster | PA | Plastics and Rubber Products Manufacturing326199 | 100-499 | ◐ LIKELY ACTIVE |
| NNobelclad | Mount Braddock | PA | Fabricated Metal Product Manufacturing332313 | 20-99 | ◐ LIKELY ACTIVE |
| NPNorma Pennsylvania | Clarksburg | PA | Fabricated Metal Product Manufacturing332510 | 100-499 | ◐ LIKELY ACTIVE |
| NANorth Amer Hoganas/johnstown Plt | Johnstown | PA | Chemical Manufacturing325510 | — | ◐ LIKELY ACTIVE |
| NANorth American Packaging LLC. dba Econo-Pak | Milford | PA | Food Manufacturing311999 | 100-499 | ◐ LIKELY ACTIVE |
| NLNovae Llc/waynesboro | Waynesboro | PA | Machinery Manufacturing333924 | — | ◐ LIKELY ACTIVE |
| OPOberg - Precision Machining Center | Sarver | PA | Miscellaneous Manufacturing339112 | 100-499 | ◐ LIKELY ACTIVE |
| OLOhm Labs, INC. | Pittsburgh | PA | Computer and Electronic Product Manufacturing334515 | 1-19 | ◐ LIKELY ACTIVE |
| OLOldcastle Lawn & Garden/quakertown | Quakertown | PA | Wood Product Manufacturing321999 | — | ◐ LIKELY ACTIVE |
| OWOlin Winchester LLC | Coal Township | PA | Miscellaneous Manufacturing339920 | 20-99 | ◐ LIKELY ACTIVE |
| OTOlson Technologies | Allentown | PA | Fabricated Metal Product Manufacturing332911 | 20-99 | ◐ LIKELY ACTIVE |
| OSOneal Steel INC | Ambridge | PA | Fabricated Metal Product Manufacturing332999 | — | ◐ LIKELY ACTIVE |
Onexia, INC. | Exton | PA | Machinery Manufacturing333998 | 20-99 | ◐ LIKELY ACTIVE |