The six incremental steps in developing Michigan's drug-dependence assessment process were the selection of a validated measure of drug dependence that is amenable to the population and environmental constraints; a pilot study of the validated measures; modification of the measure; assessment of needs and the forecasting of future service requirements; staff training in the potential uses of the assessment procedure; and the integration of the screening results with the statewide databases. A description of the steps implemented in Michigan is followed by a discussion of the indicators of successful implementation, including evidence of institutional and inmate benefits. The instrument used in Michigan's drug-dependence assessment was the Substance Abuse Subtle Inventory (SASSI-3). It is an instrument that can be administered in 20 minutes by a layperson. The assessment procedure has resulted in an improved knowledge of the treatment needs of the prison population and the obtaining of information on inmates that allows the matching of services to inmate needs. The SASSI-3 results are part of the offender's file, which follows the offender over the course of his/her institutional stay and into the community following release. There is no reason to believe that Michigan's assessment system could not be replicated in other States. 4 tables and 19 references