As wind energy use continues to expand, concern over the possible impacts of wind farms on birds continues to be an issue. The concern includes two primary areas: the effect of avian mortality on bird populations, and possible litigation over the killing of even one bird if it is protected by the Migratory Bird Treaty Act or the Endangered Species Act or both. In order to address these concerns, the U.S. Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL), working collaboratively with all stakeholders including utilities, environmental groups, consumer advocates, utility regulators, government officials, and the wind industry, has an active avian-wind power research program. DOE/NREL is conducting and sponsoring research with the expectation of developing solutions to reduce or avoid avian mortality due to wind energy development throughout the United States of America. This paper outlines the DOE/NREL approach and summarizes completed, current, and planned projects.