Results on the National Assessment for Education Progress and the Program for International Student Assessment show that high school mathematics instruction is past due for a redesign. Despite calls for reform going back at least four decades, the structure of math instruction has remained largely the same. In April 2018, the National Council of Teachers of Mathematics released Catalyzing Change in High School Mathematics: Initiating Critical Conversations to promote discussion of the changes needed. Robert Berry and Matthew Larson, current and past presidents of NCTM, describe the arguments within this report, asserting that the math curriculum needs to help students understand the mathematics that's part of daily life, that tracking of students and teachers should be abandoned, that instruction should involve all students as doers of math, and that all students should experience a common curriculum.