 Lung transplant recipients LTR experience more transplant-related complications, higher health resource utilization, and higher mortality than recipients of other solid organs. Prevention and detection of early complications is known to reduce the likelihood of future impairments in lung function and, therefore, morbidity and mortality. Despite the scarce donor organs and financial resources expended to support individuals throughout the lung transplant experience, no randomized controlled trials RCT have tested interventions designed to promote self-care behaviors with the aim of improving transplant-related health after lung transplant. The purpose of this RCT is to compare the efficacy of a novel behavioral intervention, Pocket PATH Personal Assistant for Tracking Health for promoting self-care and improving health outcomes relative to standard care after lung transplantation. Pocket PATH provides LTR a hand-held device with customized data recording, trending, and decision-support programs to promote their self-care behaviors. Based on the promising results from our early trials, a full-scale RCT has been designed to rigorously test the efficacy of Pocket PATH in promoting self-care agency, self-care behaviors, and hence improving transplant-related health. A sample of 214 LTR who survive the immediate intensive care unit recovery period will be randomly assigned to either the intervention group, who will be instructed to use the Pocket Path device and its programs designed for self-monitoring, adhering to the regimen, and communicating condition changes to the transplant team, or the control group who will receive standard instructions regarding the post-transplant regimen including health monitoring. Information will be collected from participants at baseline and 1 week, 2, 6, and 12 months after discharge from the hospital following lung transplantation. Longitudinal, repeated-measures models with planned comparisons will be used to test the hypotheses for the primary aims. It is hypothesized that subjects in the Pocket PATH group will develop higher levels of self-care agency and perform self-care behaviors more often than subjects in the control group and, therefore, will experience fewer transplant-related complications, re-hospitalizations, and better health related quality of life. 