The data used in the analyses were contributed to the National Juvenile Court Data Archive by just over 2,500 courts with jurisdiction over 87 percent of the juvenile population in 2017. The report focuses on cases that involved juveniles charged with law violations (delinquency or status offenses). A “case” is a juvenile processed by a juvenile court on a new referral, regardless of the number of law violations contained in the referral. An introductory chapter reviews the unit of count, data coverage, the nature of juvenile court processing, data quality, the validity of the estimates, data access, and other sources of juvenile court data. The report’s next two chapters present national estimates of delinquency cases processed by the juvenile courts in 2017, and they analyze caseload trends since 2005. Statistics cover the volume and rate of delinquency cases, demographic characteristics of the juveniles involved, and offenses charged. The flow of delinquency cases is traced from referral to court through court processing. The report’s fourth chapter presents national estimates of status offense cases formally handled by the juvenile courts in 2017 and caseload trends since 2005. It includes data on demographic characteristics, offenses charged, and case processing. An appendix describes the statistical procedure used to produce these estimates, and an index of tables and figures is provided.