| Code | Name | Region |
|---|---|---|
| USYKT | Yorktown | TX |
| USYKW | Yorktown | VA |
| USYKH | Yorktown Heights | NY |
| USC7Q | Yorkville | CA |
| USYRV | Yorkville | IL |
| USYAH | Yarmouth | MA |
| USYAR | Yarmouth | ME |
| USYMP | Yarmouth Port | MA |
| USYAT | Yatesboro | PA |
| USYAZ | Yazoo City | MS |
| USYVN | Yeadon | PA |
| USYT7 | Yeagertown | PA |
| USYS7 | Yellow Springs | OH |
| USYEL | Yellville | AR |
| USYYE | Yelm | WA |
| USYMA | Yemassee | SC |
| USEYR | Yerington | NV |
| USYOY | Yermo | CA |
| USYOA | Yoakum | TX |
| USYDR | Yoder | IN |
| USYEO | Yoe | PA |
| USYOK | Yoke Bay | AK |
| USYOO | Yolo | CA |
| USYON | Yonkers | NY |
| USYBL | Yorba Linda | CA |
| USWY4 | Wysox | PA |
| USWEV | Wytheville | VA |
| USXOL | Xenia | OH |
| USY9O | Yachats | OR |
| USYA2 | Yacolt | WA |
| USYAD | Yadkinville | NC |
| USYKM | Yakima | WA |
| USYAK | Yakutat | AK |
| USYAL | Yale | MI |
| USIYA | Yale | OK |
| USY4L | Yale | VA |
| USYVE | Yalesville | CT |
| USYHJ | Yamhill | OR |
| USYCY | Yanceyville | NC |
| USYKN | Yankton | SD |
| USYNI | Yantic | CT |
| USYNK | Yaphank | NY |
| USYAP | Yardley | PA |
| USYDV | Yardville | NJ |
| USYOH | Yarmouth | IA |
| USXYT | Wyatt | IN |
| USZWK | Wyckoff | NJ |
| USWM6 | Wye Mills | MD |
| USWYI | Wyemills | MD |
| USKFF | Wykoff | MN |