| Code | Name | Region |
|---|---|---|
| USJHY | Cambridge | MA |
| USCGE | Cambridge | MD |
| USB7G | Cambridge | ME |
| USCBD | Cambridge | MN |
| USCMB | Cambridge | MS |
| USC45 | Cambridge | NE |
| USCR7 | Cambridge | NY |
| USCBH | Cambridge | OH |
| USCB6 | Cambridge | VT |
| USAMG | Cambridge | WI |
| USCAM | Cambridge City | IN |
| USUFJ | Cambridge Springs | PA |
| USC4B | Cambridgeport | VT |
| USYCA | Camby | IN |
| USCDD | Camden | AL |
| USCDH | Camden | AR |
| USXAE | Camden | DE |
| USKDN | Camden | IN |
| USCAY | Calumet City | IL |
| USCUP | Calumet Park | IL |
| USVEZ | Calvert | AL |
| US8CV | Calvert | TX |
| USCCT | Calvert City | KY |
| USC42 | Calverton | MD |
| USCTO | Calverton | NY |
| USAEO | Calverton | VA |
| USXAW | Calwa | CA |
| USYDS | Calypso | NC |
| USKMM | Camak | GA |
| USCAN | Camanche | IA |
| USCMW | Camano Is. | WA |
| USCMR | Camarillo | CA |
| USCM4 | Camas | ID |
| USCMS | Camas | WA |
| USCV5 | Camas Valley | OR |
| US9CM | Cambria | IL |
| USWMB | Cambria | WI |
| USC4M | Cambridge | IA |
| USCA2 | California | MD |
| USCFJ | California | MO |
| USIFF | California | PA |
| USZTZ | California City | CA |
| USCAA | Calimesa | CA |
| USCLR | Calipatria | CA |
| USCAG | Calistoga | CA |
| USCH6 | Callahan | FL |
| USC23 | Callands | VA |
| USZBX | Callao | MO |
| USCW6 | Callaway | FL |
| USKCJ | Callaway | MN |