Washington State's new juvenile justice code calls for more fundamental and comprehensive changes than those undertaken in any other State. Principles underlying the code emphasize uniformity, equity, fairness, and accountability rather than rehabilitation or deterrence. Sentences are presumptive, determinate, and proportionate to offense seriousness. Felonies and misdemeanors involving juveniles are screened by the prosecutor's office, and commumity-based diversion programs are required for some juveniles. Juveniles who commit status offenses are no longer under the juvenile court's jurisdiction. Methodologies for assessing the code's impact 2 years after its implementation ranged from qualitative analysis of the law's history, philosophy, and rationale to multivariate analysis of decisionmaking and recidivism. The reform achieved the intended effects in organizational responsibilities and case processing. Decisionmaking at intake, filing, and sentencing were more uniform and proportionate to offense seriousness and prior record. Serious juvenile offenders were more likely to be incarcerated. Although status offenses are no longer punished, delinquents with status offense records were likely to be treated more harshly than those without such records. Recidivism could not be measured. 3 tables, 4 figures, and 28-item bibliography.