| Code | Name | Region |
|---|---|---|
| USTLZ | Stilwell | KS |
| USQSL | Stilwell | OK |
| US3SB | Stinson Beach | CA |
| USTRG | Stirling | NJ |
| USS4T | Stittville | NY |
| USSKB | Stockbridge | GA |
| USTCB | Stockbridge | MA |
| USSKG | Stockbridge | MI |
| USKGB | Stockbridge | VT |
| USSD4 | Stockdale | TX |
| USSTT | Stockertown | PA |
| USTK9 | Stockett | MT |
| US9HO | Stockholm | ME |
| USTZK | Stockton | AL |
| USSCK | Stockton | CA |
| US9SK | Stockton | GA |
| US87O | Stockton | IA |
| USTC8 | Stockton | IL |
| USS3T | Stockton | KS |
| USZSB | Stevensburg | VA |
| USSJZ | Stevenson | AL |
| USEVS | Stevenson | WA |
| USS3H | Stevenson Ranch | CA |
| USSVV | Stevensville | MD |
| USSLW | Stevensville | MI |
| USTES | Stevensville | MT |
| USF8S | Stevinson | CA |
| USTER | Stewart | AL |
| USTWT | Stewart | AL |
| USTWM | Stewart, Mcleod | MN |
| USQTW | Stewartsville | NJ |
| USSV7 | Stewartville | MN |
| USSKT | Stickney | IL |
| USVVR | Stigler | OK |
| USLLM | Stillmore | GA |
| USTIS | Stillwater | MN |
| USVSW | Stillwater | NJ |
| USIWZ | Stillwater | NY |
| USIAK | Stillwater | OH |
| USS9G | Sterling | CT |
| USSGI | Sterling | IL |
| USS8R | Sterling | KS |
| USXLS | Sterling | MA |
| USSKA | Sterling | MI |
| USRZF | Sterling | ND |
| USHZ3 | Sterling | OH |
| USSEK | Sterling | PA |
| USSGV | Sterling | VA |
| USYTE | Sterling City | TX |
| USSEH | Sterling Heights | MI |