Family members of Veterans with posttraumatic stress disorder (PTSD) face high levels of burden that are poorly addressed by existing mental health services. Widely distributed mobile interventions could play a role in addressing these unmet needs. The purpose of this study was to characterize caregiver burden in those seeking a mobile app for self-management of stress symptoms and to develop a model to guide mobile interventions for family members. Those living with a Veteran with PTSD (n = 212) and interested in using a mobile intervention agreed to participate.