| Code | Name | Region |
|---|---|---|
| USYUC | Yucaipa | CA |
| USYCC | Yucca | AZ |
| USUCC | Yucca Flat | NV |
| USYAV | Yucca Valley | CA |
| USYKO | Yukon | OK |
| USYRK | York | AL |
| USYKY | York | KY |
| USYO2 | York | ME |
| USYRN | York | NE |
| USYK8 | York | NY |
| USTHV | York | PA |
| USYOR | York | SC |
| USYKB | York Beach | ME |
| USZYH | York Harbor | ME |
| USYRH | York Haven | PA |
| USYS8 | York Springs | PA |
| USYK9 | Yorketown | NJ |
| USYRL | Yorklyn | DE |
| USYYH | Yorkshire | OH |
| USYRT | Yorktown | IN |
| 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 |