| nowrap | |- ! rowspan=2 | | Roman Pucinski | | Democratic | 1958 | | Retired to run for U.S. Senator.Democratic loss. | rowspan=2 nowrap | |- | Frank Annunzio | | Democratic | 1964 | Incumbent re-elected. |- ! | Phil Crane | | Republican | 1969 | Incumbent re-elected. | nowrap | |- ! | Robert McClory | | Republican | 1962 | Incumbent re-elected. | nowrap | |- ! | John N. Erlenborn | | Republican | 1964 | Incumbent re-elected. | nowrap | |- ! rowspan=2 | | Cliffard D. Carlson | | Republican | 1972 | | Incumbent retired.Republican loss. | rowspan=2 nowrap | |- | Leslie C. Arends | | Republican | 1934 | Incumbent re-elected. |- ! | John B. Anderson | | Republican | 1960 | Incumbent re-elected. | nowrap | |- ! | colspan=3 | None (district created) | | New seat.New member elected.Republican gain. | nowrap | |- ! | Robert H. Michel | | Republican | 1956 | Incumbent re-elected. | nowrap | |- ! | Tom Railsback | | Republican | 1966 | Incumbent re-elected. | nowrap | |- ! | Paul Findley | | Republican | 1960 | Incumbent re-elected. | nowrap | |- ! | William L. Springer | | Republican | 1950 | | Incumbent retired.New member elected.Republican hold. | nowrap | |- ! | George E. Shipley | | Democratic | 1958 | Incumbent re-elected. | nowrap | |- ! | Melvin Price | | Democratic | 1944 | Incumbent re-elected. | nowrap | |- ! | Kenneth J. Gray | | Democratic | 1954 | Incumbent re-elected. | nowrap | |} Indiana |- ! | Ray Madden | | Democratic | 1942 | Incumbent re-elected. | nowrap | |- ! | Earl Landgrebe | | Republican | 1968 | Incumbent re-elected. | nowrap | |- ! | John Brademas | | Democratic | 1958 | Incumbent re-elected. | nowrap | |- ! | J. Edward Roush | | Democratic | 19581968 1970 | Incumbent re-elected. | nowrap | |- ! | Elwood Hillis | | Republican | 1970 | Incumbent re-elected. | nowrap | |- ! | William G. Bray | | Republican | 1950 | Incumbent re-elected. | nowrap | |- ! | John T. Myers | | Republican | 1966 | Incumbent re-elected. | nowrap | |- ! |