| Abbreviation | Definition |
|---|---|
| HCPAC | Health Care Professional Advisory Committee (American Medical Association) |
| HCPOA | Howard County Police Officers Association |
| HCSA | Haliburton County Snowmobile Association |
| HCSA | Hospital Consultants and Specialists Association |
| HCSSA | Historical and Cultural Studies Student Association |
| HCSSA | Historical and Cultural Studies Students Association |
| HCTA | Hernando Classroom Teachers Association |
| HCTA | Hillsborough Classroom Teachers Association |
| HCTA | Homestead Conservation and Trails Association |
| HCTA | Hopkinton Contoocook Taxpayers Association |
| HCVA | Historic Cocoa Village Association |
| HDA | Hampshire Deaf Association |
| HDA | Holiday Decorative Association |
| HDCA | Historic Downtown Chelan Association |
| HDMA | Heavy Duty Manufacturers Association |
| HDRA | Henry Doubleday Research Association |
| HDRA | Historic Downtown Residents Association |
| HDSA | Honorary Deputy Sheriff's Association |
| HEA | Highline Education Association |
| HEA | Highline Electric Association |