For individuals with cancer, the end of active treatment and return to life ?as usual? is widely recognized as a difficult transition (IOM 2005): the physical and emotional intensity of active treatment with attendant support and structure are suddenly replaced with expectations that survivors will readily resume life just where they left off. Yet individuals vary greatly in terms of their adjustment during this critical transition point into survivorship, which can set the course of their long-term well-being. Currently, no comprehensive research explaining the underlying mechanisms and outcomes of resilience from this point has been conducted. Resilience trajectories provide a useful way to model individual differences in survivors? post-treatment adjustment. In this application, we respond to PAR-16-326, which requests elucidation of ?mechanisms and processes of resilience.? We will examine adjustment to the challenge that end of primary treatment poses to cancer patients/survivors. Based on the Social Cognitive Restorative Model of Wellbeing (Lent, 2007), we aim to determine the pre-challenge (pre-transition) biological, personal and social factors that predict trajectories of survivors? recovery and resilience in four different life domains (physical and psychological health and well- being, social functioning, and health behaviors), with multiple self-report and objective indices comprising each domain. Our prospective study proposes to follow 575 individuals diagnosed with breast, prostate, or colorectal cancer across the transition to survivorship, assessed during active treatment, within three months of completing treatment, and six, nine, and twelve months post-treatment. Participants will be recruited through the SEER Registry at Yale-New Haven Hospital. Per requirements of PAR 16-326, our project has 2 distinct phases: In the UG3 planning phase, we will establish study infrastructure, pilot-test and finalize our selection of assays, secure IRB approval, develop recruitment procedures, and train staff. For the UH3 phase, we will implement a longitudinal prospective study to test hypotheses derived from our dynamic model of resilience. Our ultimate goal is to identify processes (mechanisms) that mediate the pathways between patients? final stages of primary cancer treatment and quality of their subsequent reintegration into ?life as usual? that hold potential as targets of intervention, based on their influence on resilience trajectories. Our specific aims are to identify the different trajectories of survivors? adjustment through the transition (e.g., resilience, recovery, delayed recovery, chronic difficulties) by domain and the extent to which trajectories are related or distinct across domains, to examine predictors and processes that explain these different trajectories, and to determine if characteristics such as type of cancer or gender moderate their influences. Characterizing these trajectories, their determinants, and their underlying processes are essential for promoting resilience in survivorship and for developing effective and targeted interventions.