| HAPPI | Health Affairs Pipeline Partnership Initiative 
| Others |
| HAPPI | Health Appetite Physique Personality Inspiration
| Others |
| HAPPI | Health Assistance Program for Personnel and Industry
| Others |
| HAPPI | Healthy and Powerful Positive Individuals
| Others |
| HAPPI | Heightened Altered Past Perceptive Introspection
| Others |
| HAPPI | High Availability Peer To Peer Implementation
| Others |
| HAPPI | Highly Automated Procurement and Provisioning of Infrastructure
| Others |
| HAPPI | Horse And Petting Pal Interaction
| Others |
| HAPPI | Hospital Antibiotic Prudent Prescribing Indicators
| Others |
| HAPPI | Household and Personal Products Industry
| Others |