Rheingans returned to the United States and from 1994 to 1997 was a social studies teacher at Freeport High School in Freeport, Illinois. He then served from 1997 to 1999 as a social studies teacher and dean of students at North Scott High School in Eldridge, Iowa. In 1999 he received his master's degree in educational administration from the University of Northern Iowa. He was the principal of the junior-senior high school in Wilton, Iowa from 1999 to 2004.
Rheingans came to the Dubuque public schools in 2004. He served from then until 2012 as the Executive Director of Human Resources. He received his advanced studies certificate in superintendency from the University of Northern Iowa in the fall of 2011.
In September 2012 the Board of Education chose Rheingans to become the district's superintendent following Larie GODINEZ.
Becker, Stacey. "Rheingans Takes the Reins." Telegraph Herald, September 20, 2012