Program components to meet these goals include 3 to 4 months of incarceration, selective intake of offenders, an active caseload of 375 to 500 participants, required employment, special counseling, required payment of fines and restitution, intensive supervision contacts, revocation of failures, and community sponsor and network team support. An evaluation of the program's effectiveness, including both ongoing monitoring and comparisons between ISP participants and a sample of similar felony offenders who served their terms and were paroled, shows that ISP has been successful in meeting its objectives. ISP saved prison space, reduced per offender correctional costs, produced a high rate (93.3 percent) of full-time employment among participants, and reduced recidivism rates by over 10 percent. In addition, ISP provided a form of punishment that is intermediate in severity between an ordinary imprisonment term and ordinary probation. In view of the above, continuation of the ISP seems a wise investment of correctional resources. Glossary, tables, and 36 references.