Preventing lead exposure from all sources is critical for children’s optimal health and development. The crisis in Flint, Michigan, drew attention to the role of drinking water in lead exposure. School drinking water might pose significant risks due to aging infrastructure and the particular conditions of water use in schools. In 2016, New Jersey mandated that school districts test all drinking water outlets for lead and specified procedures that districts must follow. This study assessed compliance with this mandate. Districts were required to report results on their websites, so we used district websites as the unit of analysis to assess compliance with testing and reporting procedures and to identify schools that had reported maximum concentrations of lead in water. Most districts complied with the mandate to test their drinking water (90%) and the majority complied with online reporting requirements to some extent (87%). Most districts (79%) had one or more outlets in their district that exceeded the U.S. Environmental Protection Agency’s action level of 15 ppb. Mandated testing for lead in drinking water in schools is an important policy that can prevent childhood lead exposure. New Jersey should consider lowering the action level at which lead in drinking water should be remediated.