In response to the emerging crisis of expanded juvenile detention and its proven negative effects on the juveniles involved, the Annie E. Casey Foundation funded and launched the JDAI. JDAI's objectives are to eliminate the unnecessary use of secure juvenile detention; to minimize rearrest and failure-to-appear rates pending adjudication; to ensure appropriate conditions of confinement in secure facilities; and to redirect public financing to sustained reforms. Planned strategies include collaboration for reform; the use of accurate data to diagnose the system's problems with detention; the use of objective admissions criteria and instruments to replace subjective decisionmaking regarding detention; new or enhanced nonsecure alternatives to detention; case-processing reforms to expedite case processing; and the reduction in racial disparities in detention decisions. Several JDAI sites emerged in the demonstration phase of the JDAI. Brief descriptions of JDAI initiatives are presented for Cook County, IL; Multnomah County, OR; and Santa Cruz County, CA. JDAI is now being replicated in jurisdictions across the country, including at least eight States that are implementing reforms statewide. Lessons learned thus far are that political will is essential; capacities for reform must be created; judicial leadership is essential; the dearth of data impedes reform; successful replication require fidelity to the model; and significant change is possible.