| Society of Teachers of the Alexander Technique | Academic & Science |
| Stratospheric Tracers of Atmospheric Transport | Academic & Science |
| Send The Apple Tissue | Academic & Science |
| Student Teacher Academic Time | Academic & Science |
| Students Taking Action Today | Academic & Science |
| Students Today Alumni Tomorrow | Academic & Science |
| I Stat Corporation | Business |
| Strategic Trade Alliance Target | Business |
| Sooner Than A Tool | Business |
| Special Topic Assessment Team | Business |
| Science Teachers Association of Texas | Community |
| Student Teacher Assistance Team | Community |
| Scientist Teacher Action Teams | Community |
| Student Teacher Assistance Teams | Community |
| School Trauma Assistance Team | Community |
| Spokane Teens Against Tobacco | Community |
| Secure Timed Audit Trail | Computing |
| Security Test and Analysis Tool | Computing |
| Short Turn Around Time | General |
| Special Tertiary Admissions Test | General |
| Standing Tall and Talented | General |
| Strength To Achieve Total | General |
| Signal Transduction And Activator Of Transcription | General |
| Space Telescope Astrometry Team | General |
| Standing Together Against Trafficking | General |
| Stand Together Arizona Training | General |
| Submission Tracking and Analytics Tool | General |
| Short Topical And Timely | General |
| Signal Transduction And Activators Of Transcription | General |
| Signal Transducers And Activa Tors | General |
| Sharing Time And Talent | General |
| Speakers Today And Tomorrow Toastmasters Club | General |
| S Of The Alexander Technique | General |
| Special Tactics And Techniques | Governmental |
| United States Statutes at Large | Governmental |
| Statim (at once, immediately) | International |
| Shake That A**, Toots | Internet |
| Signal Transducers and Activators of Transcription | Medical |
| statim - immediately | Medical |
| Sooner Than Already There | Medical |
| Immediately, At Once | Medical |
| Signal Transducer and Activator of Transcription | Medical |
| Stabilization, Treatment, And Transport | Medical |
| Screening Tracing Active Transmission | Medical |
| Security Threat Avoidance Technology | Military and Defence |
| Statistical | Space Science |
| Status | Space Science |
| Summer Training Action Team | Sports |
