| Silicon In Minerals of Aluminum | Academic & Science |
| Sonics & Materials, Incorporated (de-listed) | Business |
| South Indian Maharashtrian Association | Business |
| Surf Industry Manufacturers Association | Business |
| Southern India Mills Association | Business |
| Special Import Measures Act | Business |
| Senior Insurance Marketing Association | Business |
| Strategic It Management Assessment | Business |
| System For Identifying Motivated Abilities | Community |
| South Indian Millowners' Association | Community |
| Smyrna Independent Merchants' Association | Community |
| Snow and Ice Management Association | Community |
| Snow Ice Management Association | Community |
| Social Impact Media Awards | Community |
| South Indian Music Academy | Community |
| Surf Industry Manufacturer Association | Community |
| Summer Institute in Museum Anthropology | Community |
| Support Initiative For Multimedia Applications | Computing |
| Simple Integrated Media Access | Computing |
| She Is My Angel | General |
| Systems Integration Modeling And Analysis | General |
| Shore Intermediate Maintenance Activity | General |
| Steel Import Monitoring and Analysis | General |
| Salon international de la musique africaine | General |
| Strain Induced Melt Activation | General |
| System for Identifying Method Abilities | General |
| Sustainable Integrated Multitrophic Agriculture | General |
| System for Integrated Motivational Abilities | General |
| Sumas International Motorsports Academy | General |
| Spill Impact Mitigation Assessment | General |
| Ship Intermediate Maintenance Activities | General |
| Systems Integration Management Activity | Governmental |
| Small Incremental Motion Actuator | Governmental |
| Stand for In Medical And | Medical |
| Super International Mega Ace | Sports |
| Seattle Integrated Martial Arts | Sports |
| Soccer Institute at Montverde Academy | Sports |
