Aaron Dufelmeier received an associate of science degree from Lincoln Land Community College, and a bachelor's degree in agricultural economics from the University of Illinois in 1994, specializing in farm management. While attending the University of Illinois, Dufelmeier was an active member in the Alpha Chapter of Alpha Gamma Rho. Dufelmeier earned his master's degree in crop science at the University of Illinois. He also was awarded first place for the Outstanding Graduate Student presentation at the 57th annual meeting of the North Central Weed Science Society.

Dufelmeier is currently the unit leader for University of Illinois Extension in the Morgan-Scott unit. He began serving in this capacity in October, 2002. Prior to this appointment, Dufelmeier served as the unit assistant in crop systems and horticulture from 1998 to 2000, and as a crop systems educator from 2000 to 2002. He also served as interim unit leader for the Cass-Schuyler unit during 2001.

Dufelmeier is actively involved and collaborates with several different agencies and organizations throughout Morgan and Scott counties, including Farm Bureau, Kiwanis, FSA, Jacksonville Chamber of Commerce, school districts within both Morgan and Scott counties, 4 Counties for Kids, Morgan-Scott-Greene Community Planning Group, and the Midwest Cattleman's Association.

Dufelmeier is a member of the Illinois Extension Agricultural Association and the National Association of County Agricultural Agents.

As a member of IEAA, Dufelmeier received the Action Award for the West Central Region. Dufelmeier has also received a certificate of professional development in crop sciences from the University of Illinois.