| 1 | A.f.c. MissionNot reported | Nonprofit | Not reported | Not reported |
| 2 | Abchem, Inc.Not reported | Corporation | Not reported | Not reported |
| 3 | Aero National IncNot reported | Corporation | Not reported | Not reported |
| 4 | Agricultural Purchasing and Marketing Cooperative of Washington Pennsylvania IncNot reported | Corporation | Not reported | Not reported |
| 5 | Air Fare Leasing, Inc.Not reported | Corporation | Not reported | Not reported |
| 6 | Aircraft Accounts, Inc.Not reported | Corporation | Not reported | Not reported |
| 7 | Albert Packing Co.Not reported | Corporation | Not reported | Not reported |
| 8 | Albo Motels, Inc.Not reported | Corporation | Not reported | Not reported |
| 9 | The All-inclusive Image, Inc.Not reported | Corporation | Not reported | Not reported |
| 10 | Allegheny Uplands, Inc.Not reported | Corporation | Not reported | Not reported |
| 11 | All-state Rigging, Inc.Not reported | Corporation | Not reported | Not reported |
| 12 | Allstates Investment CorporationNot reported | Corporation | Not reported | Not reported |
| 13 | Alltherm Shelters Inc.Not reported | Corporation | Not reported | Not reported |
| 14 | Alpha Educational and Historical Foundation Inc.Not reported | Nonprofit | Not reported | Not reported |
| 15 | Roush, M. G. Masonry Contractors, Inc.Not reported | Corporation | Not reported | Not reported |
| 16 | American Cine-matic CorporationNot reported | Corporation | Not reported | Not reported |
| 17 | Youth Leadership Association of Western Pennsylvania, Inc.Not reported | Nonprofit | Not reported | Not reported |
| 18 | American Land Salesman's AssociationNot reported | Corporation | Not reported | Not reported |
| 19 | American Plate & Window Glass CompanyNot reported | Corporation | Not reported | Not reported |
| 20 | The American Slav Society of Washington, PennsylvaniaNot reported | Nonprofit | Not reported | Not reported |
| 21 | American Truck Stop, Inc.Not reported | Corporation | Not reported | Not reported |
| 22 | Amvets Home Association of Washington PennsylvaniaNot reported | Nonprofit | Not reported | Not reported |
| 23 | Anderson & Pollock, Inc.Not reported | Corporation | Not reported | Not reported |
| 24 | Andy Brothers Rubber Company IncNot reported | Corporation | Not reported | Not reported |
| 25 | Apache Bowmen, IncNot reported | Nonprofit | Not reported | Not reported |
| 26 | Apostolic Church of WashingtonNot reported | Nonprofit | Not reported | Not reported |
| 27 | Apostolic Faith Chapel of Washington, Pa.Not reported | Nonprofit | Not reported | Not reported |
| 28 | Arbuckle-swift Homes, Inc.Not reported | Corporation | Not reported | Not reported |
| 29 | Arden Athletic ClubNot reported | Nonprofit | Not reported | Not reported |
| 30 | Arden Downs,incNot reported | Corporation | Not reported | Not reported |
| 31 | Arden Stainless CorporationNot reported | Corporation | Not reported | Not reported |
| 32 | Arden Strabane Corp.Not reported | Corporation | Not reported | Not reported |
| 33 | The Arden Trap and Skeet AssociationNot reported | Nonprofit | Not reported | Not reported |
| 34 | Ardlee, Inc.Not reported | Corporation | Not reported | Not reported |
| 35 | J. J. Arnold CompanyNot reported | Corporation | Not reported | Not reported |
| 36 | Automation Techniques, Inc.Not reported | Corporation | Not reported | Not reported |
| 37 | Automotive Manufacturers, Inc.Not reported | Corporation | Not reported | Not reported |
| 38 | Automotive Welding and Supply Company IncorporatedNot reported | Corporation | Not reported | Not reported |
| 39 | Ava Shoe CorporationNot reported | Corporation | Not reported | Not reported |
| 40 | Avery Methodist Church of Washington, Penna.Not reported | Nonprofit | Not reported | Not reported |
| 41 | Arts Council of Washington CountyNot reported | Nonprofit | Not reported | Not reported |
| 42 | Associate Reformed Congregation of Chartiers Cross Roads of Washington CountyNot reported | Nonprofit | Not reported | Not reported |
| 43 | Associated Interiors IncNot reported | Corporation | Not reported | Not reported |
| 44 | Bcv Corp.Not reported | Corporation | Not reported | Not reported |
| 45 | B & O Asphalt Paving, Inc.Not reported | Corporation | Not reported | Not reported |
| 46 | B & W Insurance Agency, IncNot reported | Corporation | Not reported | Not reported |
| 47 | Tylerdale Family Medicine, P.c.Not reported | Corporation | Not reported | Not reported |
| 48 | Baptist Church of WashingtonNot reported | Corporation | Not reported | Not reported |
| 49 | Barr Cannon Body Co.Not reported | Corporation | Not reported | Not reported |
| 50 | Barron Coal CompanyNot reported | Corporation | Not reported | Not reported |