| Head of Contracting Activity | Academic & Science |
| hydroxycitric acid and | Academic & Science |
| Hawthorne Christian Academy | Academic & Science |
| Hydro Citric Acid | Academic & Science |
| Hydroxy Carboxylic Acid | Academic & Science |
| Hospital Corporation Of America | Business |
| Hotel Corporation of America | Business |
| Housing Corporation Assessment | Business |
| Health Careers Academy | Business |
| Houston Contractors Association | Business |
| Health Care Agency | Business |
| Housing Corporation of Arlington | Business |
| Health Corporation of America | Business |
| Hydroxy Citric Acid | Chemistry |
| Heterocyclic Amine | Chemistry |
| Hawaii Conservation Alliance | Community |
| Handicap Children's Association | Community |
| Holiday Camp Association | Community |
| Homes and Communities Agency | Community |
| Hypertrophic Cardiomyopathy Association | Community |
| Hopkinton Center for the Arts | Community |
| Halloween Costume Association | Community |
| Hollywood Critics Association | Community |
| Hotel Credit Association | Community |
| Host Channel Adapter | Computer Hardware |
| Hub Clamping Area | Computing |
| High Contrast Addressing | Computing |
| Hybrid Cloud Assessment | Computing |
| Hybrid Code Analysis | Computing |
| Holloway Cut Advisor | General |
| Hypo Clearing Agent | General |
| Hamilton Construction Association | General |
| Hammer Call Analyzer | General |
| Home Care Aide | General |
| High Consequence Area | General |
| Helping Celebrate Abilities | General |
| Hyundai Colombia Automotriz | General |
| Hyundai Cyber Academy | General |
| Hydraulic Clutch Actuator | General |
| Hydrostatic Clutch Actuator | General |
| Heartland Corvette Association | General |
| Hawaii Corvette Association | General |
| Historic Car Art | General |
| Heartland Carwash Association | General |
| Hyundai Club Azerbaijan | General |
| Human Cell Atlas | General |
| Hope Coalition America | General |
| Heart Cell Aggregate | General |
| State Health Care Authority | Governmental |
| The High Court Of Australia | Governmental |
| Health Care Authority | Governmental |
| Hamilton Conservation Authority [Ontario, Canada] | Governmental |
| Big Spring McMahon-Wrinkle Airport | Governmental |
| Health Consumer Alliance | Governmental |
| Hazleton City Authority | Governmental |
| Health Care Administration | Medical |
| Health Care Assistant | Medical |
| Healthcare Certification Authority | Medical |
| hepatocellular adenoma | Medical |
| Historic Cost Accounting (!) | Medical |
| Home Care Assistant | Medical |
| homocysteic acid | Medical |
| Hospital Caterers Association (!) | Medical |
| Hürthle cell adenoma | Medical |
| Hybrid Capture Assay | Medical |
| H?thle cell adenoma | Medical |
| High Content Analysis | Medical |
| Health Care Aid | Medical |
| Heterocyclic Amines | Medical |
| Hospitals Corporation of America | Medical |
| Humanitarian and Civic Assistance | Military and Defence |
| High Capacity Air Ambulance | Military and Defence |
| High Current Amplifier | Radio Science |
| Big Spring, Texas USA | Regional |
| High Court of Australia | Regional |
| Hardware Configuration Audit | Space Science |
| Hill Climb Assist | Sports |
