! | Leslie C. Arends | | Republican | 1934 | Incumbent re-elected. | nowrap | |- ! | Robert H. Michel | | Republican | 1956 | Incumbent re-elected. | nowrap | |- ! | Gale Schisler | | Democratic | 1964 | | Incumbent lost re-election.New member elected.Republican gain. | nowrap | |- ! | Paul Findley | | Republican | 1960 | Incumbent re-elected. | nowrap | |- ! | Kenneth J. Gray | | Democratic | 1954 | Incumbent re-elected. | nowrap | |- ! | William L. Springer | | Republican | 1950 | Incumbent re-elected. | nowrap | |- ! | George E. Shipley | | Democratic | 1958 | Incumbent re-elected. | nowrap | |- ! | Melvin Price | | Democratic | 1944 | Incumbent re-elected. | nowrap | |} Indiana Indiana redistricted for this election, election boundary changes forced two Republican incumbents into the same district while creating a new district that was won by another Republican. |- ! | Ray Madden | | Democratic | 1942 | Incumbent re-elected. | nowrap | |- ! | Charles A. Halleck | | Republican | 1935 | Incumbent re-elected. | nowrap | |- ! | John Brademas | | Democratic | 1958 | Incumbent re-elected. | nowrap | |- ! | E. Ross Adair | | Republican | 1950 | Incumbent re-elected. | nowrap | |- ! | J. Edward Roush | | Democratic | 1958 | Incumbent re-elected. | nowrap | |- ! | William G. Bray | | Republican | 1950 | Incumbent re-elected. | nowrap | |- ! | colspan=3 | None (District created) | | New seat.New member elected.Republican gain. | nowrap | |- ! | Winfield K. Denton | | Democratic | 1954 | | Incumbent lost re-election.New member elected.Republican gain. | nowrap | |- ! | Lee H. Hamilton | | Democratic | 1964 | Incumbent re-elected. | nowrap | |- ! rowspan=2 | | Richard L. Roudebush | | Republican | 1960 | Incumbent re-elected. | rowspan=2 nowrap | |- | Ralph Harvey | | Republican | 1960 | | Incumbent lost renomination.Republican loss. |- ! | Andrew Jacobs Jr. | | Democratic | 1964 | Incumbent re-elected. | nowrap | |} Iowa |- ! | John R. Schmidhauser | | Democratic | 1964 | | Incumbent lost re-election.New member elected.Republican gain. | nowrap | |-