| Code | Name | Region |
|---|---|---|
| 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 |
| USPPS | Pennsauken | NJ |
| USPBZ | Pennsboro | WV |
| USNNJ | Pennsburg | PA |
| USQVZ | Pennsdale | PA |
| USPFJ | Pennsville | NJ |
| USQV2 | Pennsylvania Furnace | PA |
| USP87 | Penobscot | ME |
| USPR2 | Penrose | CO |
| USPN5 | Penrose | NC |
| USPNS | Pensacola | FL |
| USPB4 | Pensacola Beach | FL |
| USPNP | Pentwater | MI |
| USJUY | Pembroke | NH |
| USZPB | Pembroke Park | FL |
| USP2P | Pembroke Pines | FL |
| USPYD | Pen Argyl | PA |
| USYPJ | Penacook | NH |
| USZQ4 | Penasco | NM |
| USPGG | Pendergrass | GA |
| USPDN | Pendleton | IN |
| USPJE | Pendleton | NC |
| USPDT | Pendleton | OR |
| USPDO | Pendleton | SC |
| USPDD | Pendleton | TX |
| USD9Y | Pendroy | MT |
| USNFI | Penfield | NY |
| USPF7 | Penfield | PA |
| USULA | Peninsula | OH |
| USP9N | Penitas | TX |
| USPNR | Penn Run | PA |