525
- 52501 Ottumwa
- 52530 Agency
- 52531 Albia
- 52533 Batavia
- 52534 Beacon
- 52535 Birmingham
- 52536 Blakesburg
- 52537 Bloomfield
- 52540 Brighton
- 52542 Cantril
- 52543 Cedar
- 52544 Centerville
- 52548 Chillicothe
- 52549 Cincinnati
- 52550 Delta
- 52551 Douds
- 52552 Drakesville
- 52553 Eddyville
- 52554 Eldon
- 52555 Exline
- 52556 Fairfield
- 52557
- 52560 Floris
- 52561 Fremont
- 52563 Hedrick
- 52565 Keosauqua
- 52566 Kirkville
- 52567 Libertyville
- 52569 Melrose
- 52570 Milton
- 52571 Moravia
- 52572 Moulton
- 52573 Mount Sterling
- 52574 Mystic
- 52576 Ollie
- 52577 Oskaloosa
- 52580 Packwood
- 52581 Plano
- 52583 Promise City
- 52584 Pulaski
- 52585 Richland
- 52586 Rose Hill
- 52588 Selma
- 52590 Seymour
- 52591 Sigourney
- 52593 Udell
- 52594 Unionville
- 52595 University Park