Federal and other studies have noted that exposure to violence and substance abuse make Native American youth susceptible to becoming involved with the justice system. The Government Accountability Office (GAO) was asked to examine federal and tribal efforts to address juvenile delinquency and the barriers tribes face in doing so. This report examines: (1) federal financial assistance targeting tribes that could prevent or address juvenile delinquency; (2) the extent to which federal agencies assess the performance of selected grant programs and incorporate leading practices; and (3) the juvenile delinquency challenges tribes report facing. GAO identified relevant grant programs during fiscal years 2015 through 2018--the most recent data available when GAO began the review. GAO analyzed documents and interviewed agency officials to determine how they assessed grant program performance and conducted interviews with 10 tribes and two tribal consortia to discuss challenges with delinquency.