The nature of the literacy assessments valued in the persistent accountability climate within U.S. public education, coupled with an increasingly polarized discourse around what counts as the science of reading (SOR), have resulted in instructional gatekeeping that privileges constrained skill teaching and learning in K-3 settings. The gatekeeper phenomenon is an urgent issue of equity, with children from minoritized populations bearing the brunt of the disparity. By highlighting how commonly enacted policies and practices around assessment and accountability withhold unconstrained skill teaching and learning due to pressure to prove student success via constrained skill mastery, we demonstrate how some students, often the most marginalized, receive insufficient literacy instruction in K-3. To fully actualize an expansive definition of the SOR, an expansive definition of assessment and accountability must also be adopted - one which attends to constrained and unconstrained skills while utilizing appropriate measures to document learning beginning in the earliest grades.