The primary aim of this project is to study more closely the role played by post-release aftercare in the outcomes of criminal offenders who received in-prison substance abuse treatment. Prison-based therapeutic communities (TC) (Pelissier et al., 2001; Wexler, 1995) have demonstrated efficacy, especially when combined with post-release TC aftercare (Melnick et al., 2001). The aims of this project are important from a public health perspective as there may be treatment matching, case management, and financing factors that could be manipulated to enhance the cost-effectiveness of community-based substance abuse treatment for offenders leaving prison. It is possible that both TC and Oxford House(OH) aftercare modalities increase abstinence social support, self-efficacy, and employment, which mediate reductions in drug use, reincarceration, and health problems, but overall benefits are likely to be greater for TCs because they employ professional services and empirically based behavioral strategies. However, OHs might have advantages compared to more traditional post-incarceration modalities (e.g., low costs). Bringing scientific methods to the examination of TCs and the OH community-based recovery models for addiction might help to identify the "active ingredients" of these recovery settings.