| HACA | Haitian American Community Association 
| Others |
| HACA | Hemophilia Association of the Capital Area
| Others |
| HACA | Henderson Allied Community Advocates
| Others |
| HACA | Highbank Area Civic Association
| Others |
| HACA | Historical Armed Combat Association
| Others |
| HACA | Homestead and Agricultural Credit Aid
| Others |
| HACA | Housing Authority City Of Austin
| Others |
| HACA | Housing Authority of the City of Annapolis
| Others |
| HACA | Housing Authority of the City of Asheville
| Others |
| HACA | Housing Authority of the City of Austin
| Others |
| HACA | Housing Authority of the County of Alameda
| Others |
| HACA | Houston Air Cargo Association
| Others |
| HACA | Houston Area Carriage Association
| Others |
| HACA | Human Anti Chimeric Antibodies
| Others |
| HACA | Human Anti Chimeric Antibody
| Others |
| HACA | Human Anti-Chimeric Antibody
| Others |
| HACA | Hungarian American Cultural Association
| Others |
| HACA | Hypothermia After Cardiac Arrest
| Others |