Hanus was ordained to the priesthood on July 30, 1966. He taught scholastic theology at Conception Seminary College from 1967 to 1969. He studied moral theology at Princeton University, and there earned a Master of Arts degree in 1972. He then returned to Conception Seminary, where he served as professor of religion from 1973 to 1976. From 1974 to 1976, he was an adjunct professor of moral theology at the Pontifical University of St. Anselm in Rome. Hanus was elected the sixth abbot of Conception Abbey on January 5, 1977, and received the abbatial blessing the next day. In addition to his role as abbot at Conception Abbey, he served as Abbot President of the Swiss-American Congregation, to which the abbey belongs, from 1984 to 1987.
On July 6, 1987, Abbot Jerome was appointed the eighth Bishop of Saint Cloud by Pope John Paul II. He was consecrated on August 24, 1987 by Archbishop John Roach of Saint Paul and Minneapolis. Bishops John Joseph Sullivan of Kansas City-Saint Joseph and George Henry Speltz of Saint Cloud were the principal co-consecrators. He served in Saint Cloud for seven years.
Archbishop of Dubuque
On August 23, 1994, PopeJohn Paul II appointed Bishop Hanus as the Coadjutor Archbishop of Dubuque. Archbishop Hanus was welcomed on October 27, 1994. He spent the next year becoming acquainted with the people and institutions that made up the Archdiocese. After one year, Archbishop Kucera decided to retire. When Kucera's request was approved by the Holy See on October 16, 1995, Hanus automatically succeeded him as 11th bishop and 9th archbishop of Dubuque. Archbishop Hanus implemented a strategic planning process throughout the archdiocese. He spoke to the people of the diocese via videotaped messages played at Mass and gave the people a chance to respond and express their own views as regards the needs of the church. As a result of this process he issued a vision statement, which spelled out his hopes and plans for the archdiocese. These plans included an increased role for the laity in leadership roles throughout the archdiocese. This was necessitated by the priest shortage and changing demographics of the archdiocese. Because of these realities, Hanus has had to combine and close a number of parishes. He also had to deal with the sexual abuse crisis that has rocked the church in recent times. In the wake of a federal immigration raid at a meat processing plant in Postville, Iowa, Archbishop Hanus called for comprehensive immigration reform. He also called on those who gathered at a prayer service to remember the scriptures "to treat the alien in your midst like your brother or sister, and that when you receive the alien, the foreigner, you are welcoming Christ." Hanus submitted his resignation as archbishop for health reasons, which Pope Francis accepted. On April 8, 2013, Hanus announced that Francis had appointed Bishop Michael Owen Jackels of the Diocese of Wichita, Kansas to succeed him. Hanus acted as apostolic administrator for the Archdiocese until Jackels was installed on May 30, after which he resumed his life as a monk in Missouri.
