This paper presents a new estimate that pre-primary school closures in 2020 may cost today's young children US$ 1.6 trillion in lost earnings over their lifetimes. However, most low-and-middle income countries are leaving pre-primary education out of their responses to COVID-19. This paper also draws lessons from accelerated, bridging, and remedial programmes on how introducing or expanding these transition programmes in the early years can mitigate the long-term impact on learning from pre-primary school closures.