Hybrid effectiveness-implementation trial designs have become increasingly prevalent in implementation research. As hybrid designs enter their second decade of widespread use, the Frontiers in Health Services’ Implementation Science section launches a Research Topic to fuel the field’s discourse on the past, present, and future of hybrid designs in knowledge translation. Submissions are welcome of both Original and/or Brief Research, Review, Methods, and Perspective articles. The call addresses critical assessments of hybrid designs, innovative use of hybrid designs in current trials, and...