More than ever before, social science research identifies an array of academic and social benefits for students stemming from learning in integrated educational settings, which is even more beneficial for younger students. While some state and local education agencies may raise concerns over shifting legal principles and political apprehension in pursuing strategies that integrate students across race, socioeconomic status, and other factors, the changing demographics warrant serious inquiry into integration opportunities. This literature review surveys the landscape of K-12 integration strategies to understand what is being implemented and what is known about the design and implementation of such policies that might create more diverse schools and reduce racial isolation. Before turning to that emerging body of literature, however, it is important to understand why integration matters and the legal landscape currently around voluntary integration. [For the 2018 version of this literature review, see ED582810.]