Differentiated instruction has always been about providing every learner full opportunity to grow as much as possible academically, intellectually, and socially. A key principle of differentiation is "teaching up" (Tomlinson, 2021, 2022; Tomlinson & Javius, 2012). Teaching up is of particular importance at this moment in education because it offers a path forward on two related, lingering, and defining concerns. The first is the enduring negligence to provide equity of opportunity to students from persistently marginalized groups. The second concern is a decades-long blindness to the test-driven, impoverishing nature of curriculum and instruction that pervades today's classrooms. The two concerns are tightly bonded. It is impossible to claim a quality system of public education without placing both concerns in the foreground of educational policy and practice.