United Nations (UN) Sustainable Development Goal (SDG) Target 4.6 calls for all youth and a substantial proportion of adults to be able to read. Progress toward achieving this goal began after the World Conference on Education for All in 1990. Two decades after the conference, national governments, international donor agencies, and local and international nongovernmental organizations had built schools, trained teachers, and distributed textbooks. Though that work continues, the focus has turned to ensuring that "all children" learn to read. Achieving Target 4.6 requires reform of national education systems built up over the last three decades. This article reviews the literature that informs efforts to change education systems in ways that support early-grade reading. Now is the time to focus on reforming and strengthening the education systems that will achieve Target 4.6.