This book presents "Action Over Inertia," a recovery-orientated, strengths-based approach to address the profound disruptions in daily activities and community participation often experienced by those living with serious mental illnesses. With a focus on supported "doing", the Action Over Inertia approach engages individuals in small activity and participation efforts as an opening to making longer term and sustained changes that offer meaning and well-being. The book helps service providers develop their own knowledge of activities and the health and well-being benefits an individual might receive from activities. It also asks them to consider the biases, assumptions, and constraints that might impact their ability to implement interventions related to activity and participation. A range of worksheets, resources, vignettes, and other tools are provided to support this practice. The manual was developed from the knowledge and practice of occupational science and therapy, but it will be of interest to any mental health professional, peer-provider, administrator, or policy maker interested in promoting recovery for people with serious mental illness