| Abbreviation | Definition |
|---|---|
| SIB | State Investment Board |
| SIBs | Supplemental Income Benefits |
| SIC | Standart Industrial Classification |
| SID | Sanitary Improvement District |
| SIDS | Small Island Developing States |
| SIG | State Improvement Grants |
| SIL | Services for Independent Living |
| SIMRA | State Instructional Materials Review Association |
| SIMRA | State Interagency Missouri River Authority |
| SINIs | schools in need of improvement |
| SIP | State Implementation Plan |
| SIP | Systematic Investment Plan |
| SIPMIU | State Investment Programme Monitoring Implementation Unit |
| SIR | Southern Indiana Region |
| SIR | Spokane Indian Reservation |
| SIS | Social Impact Statement |
| SIS | Social Insurance Substitute |
| SITSD | State Information Technology Services Division |
| SJ | San Jose |
| SJ | San Juan |