| Abbreviation | Definition |
|---|---|
| IAT | Initial Acceptance Test |
| IAT | Institute for Advanced Technology |
| IAT-3 | Sagger Missile |
| IATACS | Improved Army Tactical Area Communications System |
| IATACS | Improved Army Tactical Communications System |
| IATO | Interim Authority to Operate |
| IAVM | Information Assurance Vulnerability Management |
| IAVMS | Installation Automated Vehicle Management System |
| IAW | In Accordance With |
| IB | Incendiary Bomb |
| IB | Infantry Battalion |
| IB | Instructor B |
| IB | Issue Book |
| IBA | Individual Body Armor |
| IBA | Integrated Battlefield Architecture |
| IBA | Interceptor Body Armor |
| IBAM | Introduction to Basic Army Medicine |
| IBAT | Improved BAT |
| IBB | International Broadcasting Bureau |
| IBCCS | Integrated Battlefield Command and Control Simulation |