| Psychological Assessment Inventory | Academic & Science |
| Pailin | Airport Code |
| Parrish Associates, Inc. | Business |
| Piedmont Associated Industries | Business |
| Planned Administrators Inc | Business |
| Parts Associates Inc | Business |
| Plan Administrators Inc | Business |
| Phoenix Alternatives Inc | Business |
| Policy Analysis Inc | Business |
| Professional Analysis Inc | Business |
| Plant Area Index | Business |
| Project Administration Instruction | Business |
| Personal Accidental Insurance | Business |
| Pacific American Income Shares, Inc. | Business |
| Photographers, Artists, and Illustrators | Community |
| Protection & Advocacy, Inc. | Community |
| Population Action International | Community |
| Performing Arts Institute | Community |
| Personal Artificial Intelligence | Computing |
| Platform of Artificial Intelligence | Computing |
| Pulse Accumulator Input | Computing |
| Premise Attachment Interface | Computing |
| Project Pai | Cryptocurrency |
| plus amplement informé | General |
| Professorial Advancement Initiative | General |
| Personal Activity Intelligence | General |
| Price Alignment Interest | General |
| Project And Interact | General |
| Projection And Interaction | General |
| Pentasia and All In | General |
| Personality Assessment Inventory | General |
| Palo Alto Innovation | General |
| Pesticide Active Ingredient | General |
| Practice Advancement Initiative | General |
| Play Auto Install | General |
| Personal Accident Insurance | General |
| Performance Air Intake | General |
| Peugeot Automobili Italia | General |
| Pulse Air Injection | General |
| Passione Auto Italiano | General |
| Progressive Alcohol Injection | General |
| Pompe A Injection | General |
| Pioneer Automotive Industries | General |
| Pilipinas Autogroup Inc. | General |
| People Are Idiots | General |
| Polyamide-Imide | General |
| Public Access Initiative | Governmental |
| Public Affairs Internal | Governmental |
| Payment Alliance International | Governmental |
| Pre-Approval Inspection | Governmental |
| Propaganda And Information | Governmental |
| PABAI | Indian Railway Station |
| Plasminogen Activator Inhibitor | Medical |
| Pediatric Allergy and Immunology | Medical |
| Pharmaceutical Associates Inc | Medical |
| Pharmacist Advancement Initiative | Medical |
| Physicians Advocacy Institute | Medical |
| Post Acquisition Integration | Military and Defence |
| Plans, Analysis, and Integration Directorate | Military and Defence |
| Primary Aircraft Inventory | Military and Defence |
| Process After Input | Softwares |
