| Code | Name | Region |
|---|---|---|
| USB7Y | Byron | MI |
| USYBO | Byron | MN |
| USBY7 | Byron | NY |
| USBYK | Byron Center | MI |
| US7BY | Byron Hills Estates | IL |
| USCJB | Cabazon | CA |
| USCBZ | Cabin Creek | AK |
| USC3C | Cabin Creek | WV |
| USCJ4 | Cabin John | MD |
| USCBM | Cabool | MO |
| USEQA | Cabot | AR |
| USIYS | Cabot | PA |
| USCB7 | Cabot | VT |
| USZVC | Cache | IL |
| USCC7 | Cache | OK |
| USCAC | Cactus | TX |
| USQUC | Cactus (moore County) | TX |
| USXDY | Caddo Mills | TX |
| USZBT | Butner | NC |
| USBTM | Butte | MT |
| USBU2 | Butte Meadows | CA |
| USBGH | Butternut | WI |
| USBIM | Buttonwillow | CA |
| USX8T | Buxton | ME |
| USBPU | Buxton | ND |
| USZBG | Buzzards Bay | MA |
| USTNA | Byant | AR |
| USAGB | Byant | SD |
| USJBB | Bybee | TN |
| USBYQ | Byberry | PA |
| USVBL | Byesville | OH |
| USBY5 | Byfield | MA |
| USBHA | Byhalia | MS |
| USBYM | Byram | CT |
| USOBM | Byram | MS |
| USYDW | Byrdstown | TN |
| USYRM | Byromville | GA |
| USBYR | Byron | CA |
| USUWE | Burwell | NE |
| USDBH | Bush | LA |
| USBS9 | Bushkill | PA |
| USUHN | Bushnell | FL |
| USBJL | Bushnell | FL |
| USBGC | Bushnell | IL |
| USB9S | Bushton | KS |
| USXCB | Bustleton | PA |
| USBGF | Butler | AL |
| US6BL | Butler | CA |
| USAFU | Butler | GA |
| USQUR | Butler | IL |