| Name | Phone | Category |
| Padgett Business Services | 301-979-7038 | Business Services |
| Paetec Communications | 443-573-6966 | Telecommunications |
| PATH Allegheny an Allegheny Energy Company | | Energy Services |
| Patios Today | 301-271-7808 | Patio Builders/Hardscapes |
| Paul Davis Restoration & Remodeling | (301) 846-9956 | Fire/ Water Restoration |
| Paychex | 410-581-7700 | Payroll Services |
| PB Dye Golf Club | (301) 607-4653 | Golf Club |
| Pedestal Events Group | (301) 898-8870 | Party/Events Planning |
| Penn National Insurance | (301) 797-7774 | Insurance Agencies/ Brokers |
| Performance Partners-MD | 240-277-1459 | Consultants |
| Performance Rx | (240) 626-1577 | Training/Coaching |
| Period Payroll Services | (301) 620-2820 | Payroll Services |
| Petersen's Carpet and Flooring | (301) 698-4789 | Carpet /Rug Dealers |
| The Piedmont Group | 301-676-5615 | Insurance Agencies/ Brokers |
| Planet Fitness | (301) 698-8110 | Fitness |
| Pleasants Development, Inc. | (301) 428-0800 | Construction Management |
| PNC Bank - Frederick | (301) 694-4173 | Banks/savings/loans |
| Pools, Patios and Porches | (301) 698-1200 | Swimming Pool Eqpt and Supplies |
| The PowerHouse | (301) 241-4720 | Marketing/Promotion |
| PPL Services of Frederick | (240) 344-5000 | Legal Services |
| Pre-Paid Legal Services Inc. | 561-797-6282 | Employee Benefits |
| PrimeLending, a Plains Capital Company | 301-378-2150 | Mortgage Services |
| Printing Services, Inc. | (301) 695-9477 | Printers |
| Proffitt & Associates Architects | (301) 662-8532 | Architects |
| Property Management People Inc. | (301) 694-6900 | Property Management |
| Proshred of Northern Virginia | (571) 262-7620 | Office Records-Destruction |
| Prospect Veterinary Clinic | (301) 695-1050 | Veterinarians/Veterinary Hospital |
| ProTel, AT&T Authorized Retailer | 304-264-3600 | Telephone Answering Services |
| PVI Office Furniture | (301) 694-7162 | Office Furniture |
| Pyramid Landscape and Development, Inc. | (240) 253-4640 | Lawn/Garden/Landscaping Care |