The authors argue that the primary cause of failure and success in corrections programs rests with the ways in which policies and programs have been implemented. The definition of implementation as used in this chapter is "a process of mutual adaptation between the vision and goals of those who initiate development or adoption of an innovation and the organizational or system environments in which the innovation is applied." Based on an analysis of 37 case studies that cover several types of programs, six correlates of successful implementation were identified. They are sincere motivation at program initiation, support from top leadership and each group whose cooperation is required for implementation and use, staff competence, a benefit- cost surplus, clarity of goals and procedures, and clear lines of authority. Another study (Harland, Warren, and Brown, 1979) identifies four additional conditions associated with implementation success: extent of innovation, administration- practitioner gap, procedural complexity, and structural stability. Other sections of this chapter discuss process and management as two components of implementation, the role of adaptation in increasing the fit between a program design and a setting, clarifying and shaping goals, and implementation practices that decrease the likelihood of an adequate fit between program design and setting. Other chapter sections address targeting, the importance of commitment, communication strategies that increase commitment and facilitate adaptation, and the development of necessary resources. 2 tables and 1 figure