The NDP classification system is based on nine items: history of institutional violence, severity of current offense, prior offense history, escape history, release eligibility (minimum), alcohol/drug abuse, current detainer, number of prior felony convictions, and stability factors. The evaluation aimed to determine the extent to which the NDP classification system reduced violence and escapes, the appropriateness of classification criteria, and whether items on the classification instrument were valid predictors of inmate behavior. Statistical data to validate the classification instrument were based on a systematic random sample of 1,000 inmates released from the NDP during 1987. Evaluation findings showed that implementation of the NDP classification system significantly improved the safety, efficiency, and overall management of the inmate population. Specifically, the classification system reduced escapes, suicides, and other unnatural deaths. Inmates admitted to the NDP tended to score low on most of the initial classification items, and the classification system exhibited only a moderate level of prediction. Policy recommendations are offered to improve upon the classification system, and forms used to evaluate the classification system are appended. Tables and figures