AbstractClimate change, political turmoil, and economic instability worldwide suggest that managing migration surges will be a permanent challenge for many economies. In response to the record arrival of unaccompanied migrant children at the southern border, the Biden administration used surge facilities to expedite the processing of children. We assess the effectiveness of this strategy and document reductions in the time children spent under government custody. A counterfactual analysis reveals that, in their absence, the average time to reunification would have risen from 37 to 50 days. Migration surges involving unaccompanied children underscore the urgency of identifying efficient and humanitarian strategies.