When California's students return to school this fall, schools can play a pivotal role in preventing, assessing, and addressing trauma in order to support students' well-being. We summarize the existing evidence base on multi-tiered trauma-informed practices that offer increasingly intensive tiers of support. Although many multi-tiered models of trauma-informed approaches have been implemented in schools, the evidence base demonstrating their wholescale effectiveness is limited. The most compelling evidence comes from approaches within the more intensive tiers. Moreover, most of the recent guidance on addressing trauma comes from expert and practitioner experiences and recommendations, including the novel adaptations that some schools made amid the shift to distance learning. Finally, districts and schools seeking to become trauma informed should consider establishing a coherent systemwide trauma-informed approach, including care for educators themselves.