This report summarizes research on bond strength and behavior of steel reinforcing bars under cyclic loads. The report provides a background to bond problems, discusses the main variables affecting bond performance, and describes bond behavior under cyclic loads. Two general types of cyclic loads are addressed: high-cycle (fatigue) and low-cycle (earthquake and similar). The anchorage behaviors of straight bars, hooked bars, and lap splices are included. Analytical bond models are described, design recommendations are provided for both high- and low-cycle fatigue, and suggestions for further research are given.