| UMCA | Ultra Marathon Cycling Association 
| Others |
| UMCA | Umbilical Midline Connection Assembly
| Others |
| UMCA | Undeb Myfyrwyr Cymraeg Aberystwyth
| Others |
| UMCA | Undergraduate Management Consulting Association
| Others |
| UMCA | United Masonry Contractors Association
| Others |
| UMCA | United Methodist Church of Anoka
| Others |
| UMCA | United Missionary Church of Africa
| Others |
| UMCA | United Moms Charity Association
| Others |
| UMCA | United Mountain Cur Association
| Others |
| UMCA | Universal Memory and Control Architectures
| Others |
| UMCA | Universities Mission to Central Africa
| Others |
| UMCA | Universities' Mission to Central Africa
| Others |
| UMCA | University Museum of Contemporary Art
| Others |
| UMCA | University of Missouri Center for Agroforestry
| Others |
| UMCA | University of Missouri Central Administration
| Others |
| UMCA | Unweighted Major Currency Average
| Others |
| UMCA | Upper Mandeville Canyon Association
| Others |
| UMCA | Upper Midwest Conservation Association
| Others |
| UMCA | Uraba Medellin and Central Airways
| Others |
| UMCA | Urban Marketing Corporation of America
| Others |
| UMCA | Utah Mechanical Contractors Association
| Others |
| UMCA | Utah Municipal Clerks Association
| Others |
| UMCA | Utah Muscle Car Association
| Others |
| UMCA | Utility Management and Conservation Association
| Others |
| UMCA | Utility Management Conservation Association
| Others |