In addition to his 50 years of pastoral ministry, Rev. Lindberg has served as the Presiding Pastor (Bishop) of the American Association of Lutheran Churches from 1987 until his retirement in 1999. As Presiding Pastor, he was instrumental in founding the American Lutheran Theological Seminary and served as adjunct professor in areas of church history and systematics. He also taught medieval history at Upper Iowa University.
Duane and his wife Mardell reside in Waterloo, Iowa. They are blessed with five children and eleven grandchildren. In their retirement, the Lindbergs are active in their church and the American Association of Lutheran Churches (AALC). They volunteer in their community through the Sons of Norway, Rotary, and Valley Lutheran School. They are encouraging their grandchildren in their commitment to their faith and in many activities, including academics, sports, music, and the study of the Norwegian language and culture.