Simon retired from AVCO at the age of 65, moving to Pittsboro, North Carolina. She would operate her own consulting firm, Simon Associates, from her home until 1993. After concluding her research career, she served on numerous committees and advisory boards for government agencies, universities, and corporations. The most notable positions include the Department of Commerce Committee for the National Bureau of Standards, and the committee for the National Medal of Science during the Carter administration. Simon served as the first female trustee at Worcester Polytechnic Institute, where she set up the Dorothy M. Simon Endowed Fund for Fire Safety Studies.
Simon died on March 25, 2016, at the age of 96, in her home in Pittsboro, North Carolina.