Given the importance of early literacy to long-term student success, by 2021, 41 states and the District of Columbia adopted early literacy policies to improve student literacy by the end of third grade. We use an event-study approach to examine the impact of these policies on high- and low-stakes test scores. Our results suggest that adopting an early literacy policy improves elementary students' reading achievement on high-stakes assessments, particularly in third grade and in states with comprehensive early literacy policies and third-grade retention requirements. We also find suggestive evidence that early literacy policies reduce socioeconomic and racial high-stakes achievement gaps in reading and have positive spillover effects on math achievement. However, we find little evidence of significant gains in low-stakes test scores except in states with comprehensive policies. Our findings highlight the importance of content and incentives for early literacy policies.