| Integrated Passive Device(s) | Academic & Science |
| Integrated Powerhead Demonstrator | Academic & Science |
| Insulated Patio Door | Academic & Science |
| Institute of Personnel and Development | Accounts and Finance |
| Initial Professional Development | Accounts and Finance |
| Institute for Popular Democracy | Associations & Organizations |
| Instituto Peruano del Deporte | Associations & Organizations |
| Integrated Product Development | Business |
| Investment Property Databank | Business |
| Intelligent Product Division | Business |
| Intelligent Products Division | Business |
| International Publishers Direct | Business |
| Intel Product Dealer | Business |
| Implied Probability of Default | Business |
| Impedimed Ltd | Business |
| Innovations for Peace and Development | Community |
| Instructor Professional Development | Community |
| Interdisciplinary Product Development | Community |
| International Program Development | Community |
| International Professional Development | Community |
| itial Professional Development | Community |
| Iterated Prisoner’s Dilemma | Computing |
| Interactive Pager Backup | Computing |
| Internal Pointing Device | Computing |
| Identifier Process Declaration | Computing |
| Internet Protocol Deffered | Computing |
| Impressions Per Day | Computing |
| Icon Project Document | Computing |
| Immuno Polymorphism Database | Computing |
| Inflammatory Periodontal Disease | Disease |
| Inflammatory Pelvic Disease | Disease |
| Interactive Phase Distortion | Electronics |
| Ikon Police Department | General |
| International Parking Design | General |
| In Process Damage | General |
| Individual Participant Data | General |
| Interest Payment Date | General |
| Import Promotion Desk | General |
| International Product Development | General |
| Integrated Power Module | General |
| Integrated project delivery | General |
| Initiative for Policy Dialogue | General |
| Innovative Program Delivery | General |
| Instrumentation Products Division | General |
| Image Process Design | General |
| Implicit Price Deflator | General |
| Integrated Product Design | General |
| Integral Parameter Di | General |
| Interaction Preserving Discretization | General |
| Insolvency Practitioners Direct | General |
| Inter Pupillary Distance | General |
| Intellectual Property Department | Governmental |
| Indianapolis Police Department | Governmental |
| Independence Police Department | Governmental |
| Inglewood Police Department | Governmental |
| Implicit Price Deflector | Governmental |
| Institute For Professional Development | Governmental |
| Infrastructure Planning and Design | Governmental |
| Irvine Police Department | Governmental |
| Institute for Personal Development | Governmental |
| Institute for Protein Design | Governmental |
| Institute of Protein Design | Governmental |
| International Performers Database | International |
| Internet Protocol Datagram | Internet |
| Inverse Power Distance | Maths |
| Integral Parameter Differences | Maths |
| Inline Progression Dimension | Maths |
| Image Per Dollar | Measurement Unit |
| Idiopathic Parkinson's Disease | Medical |
| Interspinous Process Decompression | Medical |
| Impulsive Personality Disorder | Medical |
| Inter Pupilary Distance | Medical |
| Intermittent Peritoneal Dialysis | Medical |
| Immediate Pigment Darkening | Medical |
| Ivasive Pneumococcal Disease | Medical |
| In-Patient Department | Medical |
| Invasive Pneumococcal Disease | Medical |
| Individual Patient Data | Medical |
| Inducing The Pleasure Dreams | Messaging |
| Issue Priority Designator | Military and Defence |
| Information Processing Division | Space Science |
| Intelligent Pulse Decoding | Telecommunication |