522
- 52201 Ainsworth
- 52202 Alburnett
- 52203 Amana
- 52205 Anamosa
- 52206 Atkins
- 52207 Baldwin
- 52208 Belle Plaine
- 52209 Blairstown
- 52210 Brandon
- 52211 Brooklyn
- 52212 Center Junction
- 52213 Center Point
- 52214 Central City
- 52215 Chelsea
- 52216 Clarence
- 52217 Clutier
- 52218 Coggon
- 52219 Prairieburg
- 52220 Conroy
- 52221 Guernsey
- 52222 Deep River
- 52223 Delhi
- 52224 Dysart
- 52225 Elberon
- 52227 Ely
- 52228 Fairfax
- 52229 Garrison
- 52231 Harper
- 52232 Hartwick
- 52233 Hiawatha
- 52235 Hills
- 52236 Homestead
- 52237 Hopkinton
- 52240 Iowa City
- 52241 Coralville
- 52242 Iowa City
- 52245 Iowa City
- 52246 Iowa City
- 52247 Kalona
- 52248 Keota
- 52249 Keystone
- 52251 Ladora
- 52253 Lisbon
- 52254 Lost Nation
- 52255 Lowden
- 52257 Luzerne