Health Savings Account 
Health Spending Account 
Health Services Administration 
Handicapped Scuba Association 
Health Savings Accounts 
Health Service Area 
Health Systems Agency 
Hollandse Signal Apparaaten 
Hydrologic Service Area 
Hazardous Substances Act 
Hill Start Assist 
Homeland Security Act 
human serum albumin 
Humane Slaughter Association 
Hydrologic Service Areas 
East African Safari Air 
habitual spontaneous abortion 
Haemangiosarcoma 
Hanford Strategic Analysis 
haplotype sharing analysis 
Hard-Sphere Approximation 
Hawaii State Assessment 
Hawker Siddeley Aviation 
Hazardous substance analysis 
Hazardous Substances Authority 
Head Side Airbag 
Head Stack Assembly 
Health and safety assurance 
Health and Safety Authority 
Health Science Authority