Having been naturalized as a United States citizen in 1941, Bernhard was inducted into the US Army in 1943 and became Assistant Bandmaster of the 445th Army Service Band, for which he wrote over one hundred arrangements. Following his discharge in 1945, he entered Cornell University, studying musicology with Donald Grout and receiving his M.A. degree in 1946. He joined the faculty of the Indiana University School of Music that same year, serving as chair of the composition department until 1974, and remaining on the faculty until his retirement in 1981. After retirement Bernhard's composing energies continued unabated, and he remained an active figure on the IU and Bloomington music scene until his death.