After the war, Bacher became director of the Laboratory of Nuclear Studies at Cornell. He also served on the U.S. Atomic Energy Commission, the civilian agency that replaced the wartime Manhattan Project, and in 1947 he became one of its inaugural commissioners. He left in 1949 to become head Division of Physics, Mathematics, and Astronomy at Caltech. He was appointed a member of the President's Science Advisory Committee (PSAC) in 1958. In 1962, he became Caltech's vice president and provost. He stepped down from the post of provost in 1970, and became a professor emeritus in 1976. He died in 2004 at the age of 99.