The disease tar spot, caused by the fungus Phyllachora maydis, was first discovered in the United States in 2015. Since 2015, tar spot has become a major corn disease in the Midwest, causing yield losses up to 60 bushels per acre in fields where it is established. The disease was confirmed via laboratory diagnosis in two counties in Kentucky in 2021. While the impact of tar spot in Kentucky is not yet known, Kentucky farmers are concerned about the disease and potential for yield loss. Confirming the presence of the disease is the first step in understanding the longer-term impact on yield and disease management in corn.