 More Americans are arrested for drug offenses than for any other crime. In 2009, over 294,000 arrests were made for possession of cocaine or heroin. Incarceration does not address the root problems and is frequently followed by relapse and re-arrest after release. In the case of opiate-dependent adults arrested for possession of heroin, one potentially effective alternative is to divert offenders to methadone maintenance treatment MMT as an alternative to adjudication of their case. MMT is an effective treatment for heroin dependence, and appears very effective for criminal offenders. However, cocaine use is common in MMT patients, including those with recent criminal justice involvement, and MMT alone is ineffective in addressing cocaine use. Continued cocaine use carries a substantial health burden and necessarily entails continued criminal activity. Thus, treatment for diverted opiate-dependent offenders should be designed to address cocaine use as well as opiate use. A Stage 1 Behavior Therapy Development project is planned over 2 years to adapt, manualize and pilot test the Therapeutic Workplace intervention for adults charged with heroin possession and offered diversion to methadone maintenance treatment as an alternative to adjudication of their case. The Therapeutic Workplace is a novel, employment-based contingency management intervention that has been very effective in promoting cocaine abstinence in adults who use cocaine persistently during methadone treatment. In the Therapeutic Workplace, participants are hired in a model workplace and required to provide drug-free urine samples to work and to earn maximum pay. Once we develop and manualize the adapted version of the Therapeutic Workplace for adults arrested for heroin possession, a pilot test will be conducted. Individuals identified by the State Attorneys office as candidates for diversion will be assessed for study eligibility. Given the high rates of injection drug use and injection-related transmission of HIV in Baltimore, this study will be restricted to injection drug users to evaluate the potential utility of this intervention in reducing HIV risk. Eligible individuals will be offered methadone maintenance in lieu of prosecution and will be required to remain in methadone treatment for 90 days. All participants will receive standard MMT, independent of whether they decide to participate in the pilot study. After beginning MMT, participants will be invited to enroll in the pilot study and randomly assigned to two study groups. Participants assigned to the Usual Care Diversion group will receive the standard MMT. Participants assigned to the Therapeutic Workplace Enhanced Diversion group will receive the standard MMT and the Therapeutic Workplace intervention. The data from this pilot study will serve as the foundation for a full-scaled randomized controlled trial. Overall, the Therapeutic Workplace could serve as a novel and ideal intervention for many heroin dependent adults involved in the criminal justice system. The use of MMT in lieu of adjudication in combination with the Therapeutic Workplace could increase drug abstinence and employment and decrease HIV risk and criminal activity in this refractory high-risk population. 