"The Successful Middle School" builds upon many decades of commitment to the middle school concept. The fifth edition of AMLE's landmark position paper amplifies the importance of responding both to young adolescents' developmental needs and to their social identities. The edition's release amidst a global pandemic and increasing protests against racial injustice reminds us that responding to the full diversity of student experience is not optional. It is critical to helping young adolescents--and indeed the world--to thrive, now and in the future. [This article was published originally in the November 2020 issue of "Bridge in the Middle," the annual journal of the European League for Middle Level Education. It is published here in "Current Issues in Middle Level Education" in collaboration with the authors, the Association for Middle Level Education, and the European League for Middle Level Education.]