| Code | Name | Region |
|---|---|---|
| USUFC | Chillicothe | MO |
| USCIY | Chillicothe | OH |
| USC3L | Chillicothe | TX |
| USRKZ | Chilmark | MA |
| USCHZ | Chiloquin | OR |
| USCNI | Chilton | WI |
| USUM9 | Chimacum | WA |
| USCI6 | Chimayo | NM |
| USCWK | Cheswick | PA |
| USCHW | Cheswold | DE |
| USXTK | Chetek | WI |
| USVAK | Chevak | AK |
| USCFY | Cheverly | MD |
| USQCC | Chevy Chase | MD |
| US3HV | Chevy Chase Heights | PA |
| USHW2 | Chewelah | WA |
| USC3N | Cheyenne | OK |
| USCY9 | Cheyenne | OK |
| USCYS | Cheyenne | WY |
| USZYN | Cheyenne Wells | CO |
| USCHI | Chicago | IL |
| USCGH | Chicago Heights | IL |
| USCRG | Chicago Ridge | IL |
| USYCH | Chichester | NH |
| USCSW | Chickamauga | GA |
| USCGW | Chickasaw | AL |
| USCHK | Chickasha | OK |
| USCKX | Chicken | AK |
| USCR5 | Chester | WV |
| USZER | Chester Center | MA |
| USTDT | Chester Depot | VT |
| USTEJ | Chester Heights | PA |
| USCPX | Chester Springs | PA |
| USCX9 | Chesterbrook | PA |
| USFHC | Chesterfield | MA |
| USCFL | Chesterfield | MI |
| USCFE | Chesterfield | MO |
| USCFG | Chesterfield | NH |
| USC7F | Chesterfield | NJ |
| USTFI | Chesterfield | SC |
| USXDR | Chesterfield | VA |
| USC2L | Chesterland | OH |
| USOOX | Chesterton | IN |
| USCWN | Chestertown | MD |
| USKCW | Chestertown | NY |
| USCUT | Chestnut | CA |
| USENH | Chestnut Hill | MA |
| USCDG | Chestnut Ridge | NY |
| USCHC | Cheshire | CT |
| US8SE | Cheshire | MA |