Frogeye leaf spot (FLS) of soybean is caused by Cercospora sojina and typically affects leaves in the upper canopy. Under favorable conditions, FLS can cause up to 35% yield loss [1]. FLS is severe when soybean is grown continuously in the same field, particularly in fields where tillage is reduced, since this is a residue- and seed-borne disease. FLS was first identified in 1924 in the southeastern United States [2] and has now spread past the northern border of Nebraska and was common across the eastern third of the state in 2017[3]. Over the past few years, generic fungicides have become available to producers at a very low cost. Even though there are newer products with multiple modes of action for management, producers are selecting single mode of action products which will push resistance to become widespread [4]. In 2019, resistance to QoI fungicides was confirmed in 10 isolates of C. sojina from 10 counties in Nebraska (Fig. 1). Fungicide resistance is a serious concern because it threatens the ability to use QoI fungicides, which are some of the most effective and widely used fungicides for managing FLS. The proposed study is aimed at: 1) developing a DNA-based method to provide rapid diagnostics to identify FLS-resistance at no direct cost to growers in the next three years, 2) developing new information on the distribution and spread of fungicide resistant FLS in Nebraska, and 3) develop educational materials and outreach programs on resistance management practices.