Major disparities in some donor deferral criteria exist among different countries, raising uncertainty about their value. This program will explore a rational framework for evaluating allogeneic blood donor eligibility to support decisions that often need to be made despite a paucity of published evidence in different countries. Differences among the United States, Canada, the European Union and Australia will be discussed for deferrals for medications, cardiovascular disease, cancer and other medical conditions. The role of regulation in different countries in determining eligibility criteria will be discussed. Following presentations by experts in each of these geographical areas, there will be open discussion to explore approaches that may lead to harmonization of deferral criteria to reach consensus on a rational approach that optimally protects blood donors and transfusion recipients while balancing any effect on the donor base.