| Code | Name | Region |
|---|---|---|
| USPI7 | Pleasant Island | AK |
| USP2L | Pleasant Lake | IN |
| USP5V | Plantsville | CT |
| USPLQ | Plaquemine | LA |
| USJRC | Plaster City | CA |
| USPTU | Platinum | AK |
| USPZD | Plato | MN |
| USPL3 | Plato | MO |
| USTJJ | Platte | MO |
| USP3E | Platte | SD |
| USPDC | Platte Center | NE |
| US2PC | Platte City | MO |
| USPJT | Plattekill | NY |
| USPLO | Platteville | CO |
| USTTZ | Platteville | WI |
| USPBX | Plattsburg | MO |
| USPLB | Plattsburgh | NY |
| USYTM | Plattsmouth | NE |
| USPUU | Plaucheville | LA |
| USPYQ | Playa Del Rey | CA |
| USPDG | Playa Vista | CA |
| USJLZ | Plaza | ND |
| USPSW | Plainview | OH |
| USPVW | Plainview | TX |
| USPVI | Plainville | CT |
| USPVG | Plainville | GA |
| USIN8 | Plainville | IN |
| USIIB | Plainville | KS |
| USXKV | Plainville | MA |
| USZG7 | Plainville | NY |
| USPNW | Plainwell | MI |
| USPZX | Plaistow | NH |
| USJDP | Plandome | NY |
| USPK7 | Plankinton | SD |
| USIP2 | Plano | IA |
| USPNO | Plano | IL |
| USPLZ | Plano | TX |
| USPCI | Plant City | FL |
| USPL9 | Plantation | FL |
| USYIT | Plantation | FL |
| USLRL | Plantersville | MS |
| US2PV | Plantersville | TX |
| USPFE | Plainfield | CT |
| USNLF | Plainfield | IA |
| USPLI | Plainfield | IL |
| USPAF | Plainfield | IN |
| USFP8 | Plainfield | MA |
| USYPD | Plainfield | NH |
| USPLF | Plainfield | NJ |
| USIFI | Plainfield | OH |