re-elected. | nowrap | |- ! | Arthur H. Greenwood | | Democratic | 1922 | Incumbent re-elected. | nowrap | |- ! | Frank Gardner | | Democratic | 1922 | | Incumbent lost re-election.New member elected.Republican gain. | nowrap | |- ! | Harry C. Canfield | | Democratic | 1922 | Incumbent re-elected. | nowrap | |- ! | Noble J. Johnson | | Republican | 1924 | Incumbent re-elected. | nowrap | |- ! | Richard N. Elliott | | Republican | 1918 | Incumbent re-elected. | nowrap | |- ! | Ralph E. Updike | | Republican | 1924 | | Incumbent lost re-election.New member elected.Democratic gain. | nowrap | |- ! | Albert H. Vestal | | Republican | 1916 | Incumbent re-elected. | nowrap | |- ! | Fred S. Purnell | | Republican | 1916 | Incumbent re-elected. | nowrap | |- ! | William R. Wood | | Republican | 1914 | Incumbent re-elected. | nowrap | |- ! | Albert R. Hall | | Republican | 1924 | Incumbent re-elected. | nowrap | |- ! | David Hogg | | Republican | 1924 | Incumbent re-elected. | nowrap | |- ! | Andrew J. Hickey | | Republican | 1918 | Incumbent re-elected. | nowrap | |} Iowa |- ! | William F. Kopp | | Republican | 1920 | Incumbent re-elected. | nowrap | |- ! | F. Dickinson Letts | | Republican | 1924 | Incumbent re-elected. | nowrap | |- ! | Thomas J. B. Robinson | | Republican | 1922 | Incumbent re-elected. | nowrap | |- ! | Gilbert N. Haugen | | Republican | 1898 | Incumbent re-elected. | nowrap | |- ! | Cyrenus Cole | | Republican | 1921 | Incumbent re-elected. | nowrap | |- ! | C. William Ramseyer | | Republican | 1914 | Incumbent re-elected. | nowrap | |- ! | Cassius C. Dowell | | Republican | 1914 | Incumbent re-elected. | nowrap | |- ! | Lloyd Thurston | | Republican | 1924 | Incumbent re-elected. | nowrap | |- ! | Earl W. Vincent | | Republican | 1928 | | Incumbent lost renomination.New member elected.Republican hold. | nowrap | |- ! | Lester J. Dickinson | | Republican | 1918 | Incumbent re-elected. | nowrap | |- ! | William D. Boies | |