State K-12 assessments may soon include measures for college readiness, as California's already do. We seek to understand how California's Early Assessment Program (EAP, designed to assess high school juniors' college readiness in English and math) may have influenced overall school-level college readiness and state accountability outcomes. Using administrative data, we first examine variation in EAP participation across California's public high schools and what accounts for the variation in the early years of the program. Second, we ask whether different levels of EAP participation have influenced school outcomes. Finally, we ask whether the EAP has led to changes in schoolwide accountability measures by increasing eleventh-grade students' testing performance. We find that schools with higher participation in these aligned assessments witnessed small improvements on the state's primary accountability metric, but not through raising individual stakes for students. Results have important consequences for policymakers and education leaders designing and implementing Common Core State Standards with college-readiness assessments.