Systems to provide feedback regarding treatment progress have been recognized as a promising method for the early identification of patients at risk for treatment failure in outpatient psychotherapy. The feedback systems presented in this article rely on decision rules to contrast the actual treatment progress of an individual patient and his or her expected treatment response (ETR). Approaches to predict the ETR on the basis of patient intake characteristics and previous treatment progress can be classified into two broad classes: Rationally derived decision rules rely on the judgments of experts, who determine the amount of progress that a patient has to achieve for a given treatment session to be considered “on track.” Empirically derived decision rules are based on expected recovery curves derived from statistical models applied to aggregated psychotherapy outcomes data. Examples of each type of decision rule and of feedback systems based on such rules are presented and reviewed