The IIP is an intervention program designed to promote lawful behavior in criminal offenders through a highly structured program of discipline. Intended to develop responsibility, self-esteem, and positive self-concept, the program also addresses the underlying issues that lead to criminal behavior and substance abuse. The IIP facilities are located at Dixon Springs in the Shawnee National Forest in southeastern Illinois, in Greene County in central Illinois, and at the DuQuoin State Fairgrounds in southern Illinois. The IIP has been operating at full capacity since January 1991. Judges have referred 24,577 offenders to the IIP. Of this number, 17,349 have been admitted to the program. The typical IIP inmate is a 22-year-old black male with an 11th grade education and a history of substance abuse. He has been convicted of a property or drug offense and is serving a 4.2-year sentence. Seventy-two percent (12,167 inmates) of all program exits have graduated from the program. Of those graduates who have been released for a 3-year period, 25.7 percent have returned to prison with a new felony offense; the expected recidivism rate for comparable inmates is 35.7 percent. Since the IIP was implemented in October 1990, over $40 million has been saved due to the shorter prison stay of the participants, and projected prison crowding has been eased. 6 tables, 5 figures, 20 references, and appended program description process flow, aggregate statistics since implementation, and recidivism rates