| Seneca Resources Company, LlcHarrisburg, PA · Not reported | Harrisburg, PA | LLC | Not reported | Not reported |
| Arden Landfill, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Marts & Lundy IncorporatedHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Marubeni America CorporationHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Masonry Contractors Association of Central PennsylvaniaHarrisburg, PA · Not reported | Harrisburg, PA | Nonprofit | Not reported | Not reported |
| Mast-lepley Silo Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mathies Coal CompanyHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Olin CorporationHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mattern's Hatchery, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| George S. May International CompanyHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mazza Vineyards, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mccrackin Ford, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| James Mchugh Construction CoHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Rexam Beverage Can CompanyHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mcknight Plaza IncHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Meadowgreen CorporationHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Media Lodge No. 2189, Loyal Order of MooseHarrisburg, PA · Not reported | Harrisburg, PA | Nonprofit | Not reported | Not reported |
| Mellon Leasing CorporationHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Melville Realty Company IncHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Cigna Direct Marketing Company, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mercy Catholic Medical Center of Southeastern PennsylvaniaHarrisburg, PA · Not reported | Harrisburg, PA | Nonprofit | Not reported | Not reported |
| Meridian Associates, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mersol, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mestek, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Metal Cladding IncHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mi Windows and Doors, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Metcalf & Eddy, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Michel's Bakery, LlcHarrisburg, PA · Not reported | Harrisburg, PA | LLC | Not reported | Not reported |
| Microband Corporation of AmericaHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| The Microfilm CorporationHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mid-valley, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Middleburg Lodge No. 1229 Loyal Order of MooseHarrisburg, PA · Not reported | Harrisburg, PA | Nonprofit | Not reported | Not reported |
| Mifflinburg Lodge No 1396 Loyal Order of MooseHarrisburg, PA · Not reported | Harrisburg, PA | Nonprofit | Not reported | Not reported |
| Mylan Pharmaceuticals Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mileasing CompanyHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Milford Hall Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Millcreek Mall Corp.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Miller Transfer and Rigging Co.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Millersburg Lodge No. 59 Loyal Order of Moose, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Nonprofit | Not reported | Not reported |
| Millerstown Lodge No. 925 Loyal Order of Moose, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Nonprofit | Not reported | Not reported |
| The Millgard CorporationHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Wawa, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Old Mppc in Pa, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mitsubishi International CorporationHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mobile Dredging & Video Pipe, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Meenan Oil LlcHarrisburg, PA · Not reported | Harrisburg, PA | LLC | Not reported | Not reported |
| Mohawk Data Sciences Corp.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mollenberg-betz Machine CompanyHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Mon River Towing, Inc.Harrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |
| Monongahela Power CompanyHarrisburg, PA · Not reported | Harrisburg, PA | Corporation | Not reported | Not reported |