The third wave of cognitive behavioral therapy and the rise of processbased careThe term cognitive behavioral therapy (CBT) identifies a family of interventions that are widely recognized as the set of psychological treatments with the most extensive empirical support 1 . CBT is not monolithic, however, and it has been through several distinct eras, generations, or waves. The first generation of this tradition was behavior therapy: the application of learning principles to well-evaluated methods designed to change overt behavior. By the late 1970s, behavior therapy had moved into the era of classic CBT: a new generation of methods and concepts focused on the role of maladaptive thinking patterns in emotion and behavior, and the use of methods to detect and change those patterns. The arrival of a "third wave" of CBT was declared 13 years ago 2 . The claim was that a change was occurring in orienting assumptions within CBT, and that a set of new behavioral and cognitive approaches were emerging based on contextual concepts focused more on the persons' relationship to thought and emotion than on their content. Third wave methods emphasized such issues as mindfulness, emotions, acceptance, the relationship, values, goals, and meta-cognition. New models and intervention approaches included acceptance and commitment therapy, dialectical behavior therapy, mindfulness-based cognitive therapy, functional analytic psychotherapy, metacognitive therapy, and several others.The idea that a "third wave" of CBT had arrived led to significant controversy 3 . The metaphor of a "wave" suggested to some that previous generations of work would be washed away, but that was not the intent and that was not the result. Waves hitting a shore assimilate and include previous wavesbut they leave behind a changed shore. It seems to us that we are now in a position to begin to evaluate what will be left behind in a more permanent way from third wave CBT. There is no doubt that several concepts and methods that have been central to third wave interventions (mindfulness methods; acceptance-based procedures; decentering; cognitive defusion; values; psychological flexibility processes) are now permanently part of the CBT tradition and indeed of evidence-based therapy more generally, in large part because evidence suggests that they are helpful 4 . These newer concepts and methods now largely co-exist side by side with previously established ones, with the dialectic between them serving as a useful spur to theoretical and technological investigation. In some cases, we now know that traditional CBT methods work in part by changing processes that became central after the arrival of third wave methods 5 . Third wave methods have been added to packages that include traditional behavioral and cognitive methods, resulting in useful approaches 6 . Research has begun to identify moderators indicating when older and newer methods work best with different populations 7 , suggesting that evidence-based practitioners can serve their clients by knowing method...