| Business | Phone |
| Afl-Cio 92 Cumberland 21502 | (301) 724-0010 |
| American Postal Workers Union 215 Park St, Cumberland 21502 | (301) 724-6474 |
| Carpenters Apprenticeship 401 N Centre St, Cumberland 21502 | (301) 777-3004 |
| Communications Workers-America 426 N Centre St, Cumberland 21502 | (301) 724-2109 |
| Cumberland Firefighters Local 800 Frederick St, Cumberland 21502 | (301) 784-1715 |
| Laborers International Union 119 S Centre St, Cumberland 21502 | (301) 777-2880 |
| National Assn-Letter Carriers 152 N Mechanic St, Cumberland 21502 | (301) 722-6817 |