In 2015, Wisconsin began mandating the ACT college entrance exam and the WorkKeys career readiness assessment. With population-level data and several quasi-experimental designs, we assess how this policy affected college attendance. We estimate a positive policy effect for middle/high-income students, no effect for low-income students, and greater effects at high schools that had lower ACT participation before the policy. We further find little evidence that being deemed college-ready by one's ACT scores or career-ready by one's WorkKeys scores affects college attendance probabilities. Pragmatically, the findings highlight the policy's excellence and equity consequences, which are complex given that the policy has principally helped advantaged students. Theoretically, the findings shed light on students' (dis)inclinations to update educational beliefs in light of new signals. [This is the online version of an article published in "Educational Researcher."]