We reviewed the literature on function-based interventions (FBIs) implemented by school personnel in K-8 general education settings with a focus on intervention implementation. We identified 34 studies (70 students and FBIs) that met criteria for this review. For more than half of studies and participants, FBIs were implemented by general education teachers, delivered to male students in grades K-5, and involved both antecedent- and consequence-based strategies. Intervention fidelity was measured in 20 studies (59%). Teacher-training procedures were described in only 14 studies (41%), and researcher implementation fidelity of the teacher-training procedures was not measured in any studies. Application of Council for Exceptional Children quality indicators led to an evidence-based classification of "insufficient evidence" due to no studies meeting 100% of the quality indicators. However, 8 studies met greater than 75% of the quality indicators and established at least 1 functional relation between a teacher-implemented FBI and student challenging behavior.