School attendance is strongly associated with academic success and high school completion, but approximately one in seven students miss nearly one month of school each year. To address chronic absenteeism, we partnered with four public school districts in the metro-Atlanta area and experimentally deployed email and text messages to inform parents about their child’s attendance. Parents received personalized monthly messages through the school districts’ existing messaging platforms that have zero marginal cost per message. The messages informed parents about their child’s number of absences and how that number compares to the absences of their peers (in percentile terms). We find that receiving these messages reduced end-of-year absences by almost one day (5 percent) and reduced the probability of chronic absenteeism by 7.8 percent. However, we also find that parents of students most in need of improved attendance were the hardest to reach.