Green School Programs are an internationally recognized effort that transforms schools into environmentally friendly entities and engage school communities in environmentally impactful efforts. Such efforts may increase student awareness about their connection to the environment and have the potential to increase achievement through opportunities for hands-on science learning. This study utilizes publicly available data on public schools and student outcomes to examine the extent to which the Green School designation in Maryland is related to changes in science proficiency. Specifically, methods entailed using mixed regression of school-level science proficiency rates on the number of years as a Green School and predictive school characteristics to determine the association between time as a Green School and student science outcomes over two decades. This study improves upon existing research with timely data and methods to account for factors that may have biased previous findings.