This article presents a synthesis of reports and research on K-12 blended teaching competencies compared with K-12 online teaching competencies. The skills needed to teach in online and blended environments are distinct from traditional teaching, but teacher education programs often do not equip preservice teachers for the new modes of instruction. Additionally, there is a dearth of research on blended teaching competencies. This review synthesizes 8 blended teaching documents and 10 online teaching documents. Seven global themes identified in both competency domains are (1) pedagogy, (2) management, (3) assessment, (4) technology, (5) instructional design, (6) dispositions, and (7) improvement. The top 20 blended teaching skills include flexibility and personalization, mastery-based learning, data usage and interpretation, learning management system usage, online discussion facilitation, and software management. The authors recommend that researchers collect more methodologically transparent data about blended teaching and that teacher education programs include the identified skills in curriculum.