Following graduation from high school, Donald Spiess continued his education at Blinn College and at Sam Houston State University. After four decades in the insurance industry, in 2014 Donald retired and sold Spiess Insurance Agency/Local Chapter 14.

Donald Spiess has served on the Board of Germania Farm Mutual Insurance Association since 1983, and is active on its subsidiary boards and committees. In 2010 he was recognized by the National Association of Mutual Insurance Companies for completing the Farm Mutual Director Certification program.

He currently serves as a director for Brenham National Bank. Donald and his wife, Gwen, are members of First United Methodist Church in Brenham, where he has served on various church committees. Past community involvements include the Washington County Heart Association, chairman of the local drive for March of Dimes, and director of the Washington County Chamber of Commerce.