It has been well-documented that drug arrests are a major factor in increases in jail and prison populations. In light of this, there is a growing interest in treatment programs, both in and out of custody. However, there is a debate regarding the effectiveness of drug treatment programs in reducing recidivism and drug use. The question of whether jail drug treatment is a cost-effective investment depends in part on the results achieved by the program, whether through reduced recidivism or lowered in-custody incident rates. If recidivism is lower for participants than for comparable nonparticipants, then we can assume that the higher "costs" of these programs are offset by tangible savings to the criminal justice system and by less tangible, but significant savings to the community.