| Acronym | Definition |
|---|
| IA | Iowa (US postal abbreviation) |
| IA | Internet Archive |
| IA | Interactive |
| IA | Information Assurance |
| IA | Information Architecture |
| IA | International Airport |
| IA | Intel Architecture |
| IA | Impact Assessment |
| IA | International Affairs |
| IA | Internet Access |
| IA | International Academy |
| IA | Industrial Automation (Star Wars, company who made R2-D2) |
| IA | Internal Affairs |
| IA | Investment Advisor |
| IA | Individual Assistance (US DHS/FEMA) |
| IA | Inter Alia (Latin: among other things) |
| IA | Internal Audit |
| IA | Irrigation Association |
| IA | Italian American |
| IA | Immediate Action (Military) |
| IA | Intangible Assets |
| IA | Inspection Académique (France) |
| IA | Internet Appliance |
| IA | Inspection Authorization |
| IA | Individual Account |
| IA | Inter-Agency |
| IA | Illegal alien |
| IA | Initial Assessment |
| IA | Instruction and Assessment |
| IA | Intelligent Agent |
| IA | Implementation Agreement |
| IA | Indian Airlines |
| IA | Independent Agencies |
| IA | Immunoassay |
| IA | Intelligence Artificielle (French) |
| IA | Investment Analysis |
| IA | Isaac Asimov (author) |
| IA | Identification and Authentication |
| IA | Indian Army |
| IA | Im Auftrag (German: By Order) |
| IA | Inshallah (God willing) |
| IA | Internal Assessment (International Baccalaureate testing) |
| IA | Initial Attack (firefighting) |
| IA | Instructional Assistant |
| IA | Industry Automation |
| IA | Intelligence Analyst |
| IA | In Absentia (Latin: On Behalf of and in the Absence Of) |
| IA | Information Assistance |
| IA | Implementing Agency |
| IA | Invasive Aspergillosis |
| IA | Intraarterial |
| IA | Individual Augmentee |
| IA | Interagency Agreement |
| IA | Independent Assessment |
| IA | Interfaith Alliance |
| IA | Institute of Astronomy |
| IA | Initial Appointment |
| IA | Imperial Army (gaming) |
| IA | Internet Audio |
| IA | Institute of Aging |
| IA | India Abroad (newspaper) |
| IA | Information Asset |
| IA | Information Analyst |
| IA | Italian Army |
| IA | Industrial Archaeology |
| IA | Instantly Available |
| IA | International Alert (UK peacebuilding organization) |
| IA | Information Appliance |
| IA | Interface Adapter |
| IA | Installment Agreement |
| IA | Intelligence Assessment |
| IA | Investment Agreement |
| IA | Intruder Alert |
| IA | Iraqi Airways (IATA airline code) |
| IA | Issuing Agency |
| IA | Intelligent Application |
| IA | Initial Action |
| IA | Imperial Academy (Star Wars) |
| IA | Interval Arithmetic |
| IA | Incentive Award |
| IA | International Alphabet |
| IA | Instrumentation Amplifier |
| IA | Individual Augmentation |
| IA | Interface Analysis |
| IA | Intelligence Amplification |
| IA | Initial Appraisal (USACE) |
| IA | Industrial Attachment |
| IA | Internet Alliance |
| IA | Instrument Airplane |
| IA | Imperial Age |
| IA | Island Alliance (Boston, Massachusetts) |
| IA | It's Academic |
| IA | Incremental Analysis |
| IA | Ion-Acoustic |
| IA | Industrial Affiliates |
| IA | Integrity Agreement |
| IA | Interface Architect |
| IA | Initial Authorization |
| IA | Internal Alarm |
| IA | Information Attack |
| IA | Implementing Arrangement |
| IA | Impulse Approximation (electron momentum density) |
| IA | Infamous Adventures (gaming website) |
| IA | Implementing Agent |
| IA | Invasion America (Dreamworks TV Series) |
| IA | Integrated Agent |
| IA | Interstellar Alliance (Babylon 5) |
| IA | Imperator Augustus (Latin: Emperor Augustus, epigraphy) |
| IA | Intermediate Agent (networking) |
| IA | Interoperability Agreement |
| IA | Irrigation/Aspiration (medical procedures) |
| IA | Instructor/Advisor |
| IA | Institutional Adaptation (US Army) |
| IA | Ineffective Attempt |
| IA | Input Axis |
| IA | Interface Agreement |
| IA | Indicated Altitude |
| IA | Interim Accreditation |
| IA | Indian Airways |
| IA | Installation Assessment |
| IA | Investigative Analyst |
| IA | Inhalation Anaesthetics (pharmaceutical industry) |
| IA | Instituti Albanologjik (Albanological Institute, Kosova) |
| IA | Image Amplifier |
| IA | Impedance Angle |
| IA | Inherent Availability |
| IA | Interior Alliance (Kamloops, British Columbia, Canada) |
| IA | Internet Aid |
| IA | Instable Angina (cardiology) |
| IA | Irritant Agent |
| IA | Inventory Automation |
| IA | Installing Activity |
| IA | Interrogation Arm (explosive detection aid) |
| IA | Interactive Accountability |
| IA | Input Acknowledgement |
| IA | Imagery Analysis/Analyst |
| IA | Implosion-Assembled (weapon) |
| IA | Introducing Advisor (foreign exchange) |
| IA | Ifugao Academy (Kiangan, Ifugao, Philippines) |
| IA | Immediately Avaliable |
| IA | Installation Accountant |
| IA | Institutional Advancement (various schools) |