| Code | Name | Region |
|---|---|---|
| USAKS | Parkston | SD |
| US4RK | Parkton | MD |
| USPKT | Parkton | NC |
| USPK4 | Parkville | MD |
| USKLE | Parkville | MO |
| USPW2 | Parkwater-spokane | WA |
| USPGW | Parkwood | PA |
| USPAR | Parlier | CA |
| USPUJ | Parlin | NJ |
| USQPA | Parma | ID |
| USPAM | Parma | MI |
| USPKC | Park City | IL |
| USPC9 | Park City | KS |
| USPC6 | Park City | KY |
| USPAC | Park City | UT |
| USPKF | Park Falls | WI |
| USPFO | Park Forest | IL |
| USPH6 | Park Hill | OK |
| USPKH | Park Hills | MO |
| USPKJ | Park Junction | PA |
| USPKD | Park Rapids | MN |
| USPKG | Park Ridge | IL |
| US9PR | Park Ridge | NJ |
| USAAZ | Parker | AZ |
| USZKR | Parker | CO |
| USP6K | Parker | SD |
| USPK9 | Parker | VA |
| USPKW | Parker | WA |
| USPKR | Parker Ford | PA |
| USPA4 | Parkers Lake | KY |
| USPKB | Parkersburg | WV |
| USP9R | Paradise | KS |
| US3PL | Paradise | PA |
| USVPD | Paradise | TX |
| USPDV | Paradise Valley | AZ |
| USP2V | Paradise Valley | NV |
| USQPG | Paragon | IN |
| USPGR | Paragould | AR |
| USPMQ | Paramount | CA |
| USPRM | Paramus | NJ |
| USPZM | Parchment | MI |
| USPDF | Pardeeville | WI |
| USPS5 | Paris | AR |
| USPRP | Paris | IL |
| USPZT | Paris | KY |
| USP7S | Paris | ME |
| USPHT | Paris | TN |
| USPRX | Paris | TX |
| USP3H | Parish | FL |
| USPSU | Parish | NY |