This brief is one in a series aimed at providing K-12 education decision makers and advocates with an evidence base to ground discussions about how to best serve students during and following the novel coronavirus pandemic. Learning losses are likely to show up differently across grades and subjects, with intensive recovery needs concentrated in the early grades and among already struggling students. Supportive school environments and strong teacher-student relationships speed recovery from learning loss. High-dosage tutoring that is directly tied to classroom content -- helping students succeed in their coursework -- can substantially accelerate learning in both math and reading for the most struggling students. Extended learning time interventions, including weeklong acceleration academies staffed with highly effective teachers and some double dose math structures, show strong evidence of effectiveness. Strong systems to monitor for early student warning signs paired with strong norms and routines help students recover emotionally and engage academically. Compressed content, grade retention, and enhanced Response to Intervention (RTI) show less evidence that they substantially shift learning outcomes for struggling students, and some have potential adverse long-term consequences.