| Code | Name | Region |
|---|---|---|
| USYPB | Peterborough | NH |
| USPEE | Peterman | AL |
| USPR3 | Perkins | OK |
| USKDS | Perkinston | MS |
| USP9K | Perkinsville | VT |
| USKMV | Perkiomenville | PA |
| USPRI | Perrine | FL |
| USP7V | Perrineville | NJ |
| USPIO | Perrinton | MI |
| USPER | Perris | CA |
| USFPY | Perry | FL |
| USPYG | Perry | GA |
| USPRO | Perry | IA |
| US9PE | Perry | ME |
| USIPE | Perry | MI |
| USNYP | Perry | NY |
| USPQY | Perry | OH |
| USPRR | Perry | OK |
| USPY3 | Perry | SC |
| USWJ3 | Perry Hall | MD |
| USPYL | Perry Island | AK |
| USPYB | Perryman | MD |
| USJNL | Penwell | TX |
| USPEI | Peoria | AZ |
| USJPO | Peoria | IA |
| USPIA | Peoria | IL |
| USJP9 | Peoria | OH |
| USPHB | Peoria Heights | IL |
| USPST | Peosta | IA |
| USPJN | Peotone | IL |
| USWX7 | Pepin | WI |
| USP4K | Pepper Pike | OH |
| USPEP | Pepperell | MA |
| USPQN | Pequannock | NJ |
| USQKA | Pequea | PA |
| USPQK | Pequot Lakes | MN |
| USPE7 | Peralta | NM |
| USXPE | Perdue Hill | AL |
| USP9E | Perham | ME |
| USXKJ | Perham | MN |
| USPKS | Perkasie | PA |
| USPKQ | Perkins | AR |
| USPEN | Penndel | PA |
| US9DK | Penngrove | CA |
| USNIG | Pennington | AL |
| USPGT | Pennington | AR |
| USNNG | Pennington | NJ |
| USXKK | Pennington Gap | VA |
| USP2K | Pennock | MN |
| USPGP | Penns Grove | NJ |