| Business | Phone |
| Clsi 5111 Pegasus Ct, Frederick 21704 | (301) 662-1799 |
| Facility Design Group Inc 8329 Ball Rd, Frederick 21704 | (301) 662-4500 |
| Fox & Assoc Inc 82 Wormans Mill Ct # G, Frederick 21701 | (301) 695-0880 |
| Glm Engineering Inc 4987 Winchester Blvd # 4, Frederick 21703 | (301) 874-6175 |
| Harris Smariga & Assoc Inc 125 S Carroll St # 100, Frederick 21701 | (301) 662-4488 |
| John E Harms Jr & Assoc Inc 41 E All Saints St # 210, Frederick 21701 | (301) 631-2027 |
| Loiederman Soltesz Assoc 7 N Market St # 300, Frederick 21701 | (301) 696-1240 |
| Rothenhoefer Engineers 1317 Orchard Way # 5, Frederick 21703 | (301) 662-0202 |
| Thomas-Moore & Assoc Inc 129 W Patrick St # 13, Frederick 21701 | (301) 698-9788 |