Von Moos was a member of the cantonal government of Obwalden from 1946 to 1959. He was elected to the Federal Council of Switzerland on 17 December 1959 and handed over office on 31 December 1971. He was affiliated to the Conservative-Christian-Social People's Party (Konservativ-Christlichsoziale Volkspartei) (name from 1957–1970, today the Christian Democratic People's Party (CVP/PDC)).