| APSI | Action Plan for School Improvement 
| Others |
| APSI | Advance Placement Summer Institute
| Others |
| APSI | Advanced Placement Summer Institute
| Others |
| APSI | Advanced Placement Summer Institutes
| Others |
| APSI | Advocacy and Protective Services Inc
| Others |
| APSI | Advocacy and Protective Services, Inc.
| Others |
| APSI | Aimer Por Servir International
| Others |
| APSI | Aircraft Propulsion Subsystem Integration
| Others |
| APSI | Aker Philadelphia Shipyard
| Others |
| APSI | Alienation of Personal Services Income
| Others |
| APSI | Alliance Power Solutions Inc
| Others |
| APSI | Alltek Project Solutions Integration
| Others |
| APSI | American Plumbing Supply International
| Others |
| APSI | Amicassa Process Solutions Inc
| Others |
| APSI | Anterior-Posterior Stability Index
| Others |
| APSI | AP Summer Institute
| Others |
| APSI | Aqua Power Systems Inc
| Others |
| APSI | Asian Pacific Studies Institute
| Others |
| APSI | Asian/Pacific Studies Institute
| Others |
| APSI | Association of Plastic Surgeons of India
| Others |
| APSI | Austin Plastic Surgery Instititute
| Others |
| APSI | Austin Plastic Surgery Institute
| Others |
| APSI | Austin Plastic Surgery Institute Inc.
| Others |
| APSI | Australian Professional Skills Institute
| Others |
| APSI | Australian Professional Snowsport Instructors Inc.
| Others |
| APSI | Auto Parts Specialist Inc
| Others |
| APSI | Aviation Professionals Sharing Information
| Others |