In August 2016, several leaders in glucagon biology gathered for the European Association for the Study of Diabetes Hagedorn Workshop in Oxford, England. A key point of discussion focused around the need for basal insulin to allow for the therapeutic benefit of glucagon blockade in the treatment of diabetes. Among the most enlightening experimental results presented were findings from studies where glucagon receptor-deficient mice were administered streptozotocin to destroy pancreatic beta cells or had undergone diphtheria toxin-induced beta cell ablation. Here, key features of the discussion are summarized as we reached a consensus. Agents that antagonize glucagon may be of great benefit for the treatment of diabetes; however, sufficient levels of basal insulin are required for their therapeutic efficacy.