This StateScan publication is an update in a series that distills knowledge from NCJJ’s Juvenile Justice Geography, Policy, Practice & Statistics website (jjgps.org). The publication summarizes the results of a statutory analysis of lower, upper, and extended age of delinquency and original juvenile court jurisdiction for all 50 states, the District of Columbia, and U.S. territories (American Samoa, Guam, Northern Mariana Islands, Puerto Rico, and the Virgin Islands). The author provides a brief overview of how age boundaries for delinquency create the foundation for juvenile justice, historic and current policy trends among the states, and court jurisdiction over alleged law violations that are not considered delinquent acts [status offenses, exclusions, and transfers to (adult) criminal court, and those under original municipal court jurisdiction].