Objectives: To estimate the annual costs of psychosis in Australia from societal and government perspectives and assess whether average costs per person differ by principal service provider at time of census. Methods: Costs of psychosis encompassing health sector costs, other sector costs, and productivity losses were assessed for 2010 using a prevalence-based, bottom-up approach. Resource use data were obtained from the second Australian National Survey of Psychosis and unit costs were from government and non-government organization (NGO) sources. Costs to society were assessed by principal service provider at census: public specialized mental health services (PSMHS) and NGOs during the census month (current clients), and PSMHS in the 11 months preceding census (recent clients), and any differences were ascertained. Results: The average annual costs of psychosis to society are estimated at 77,297 per affected individual, comprising 40,941 in lost productivity, 21,714 in health sector costs, and 14,642 in other sector costs. Health sector costs are 3.9-times higher than those for the average Australian. Psychosis costs Australian society 4.91 billion per annum, and the Australian government almost 3.52 billion per annum. There are significant differences between principal service providers for each cost category. Current PSMHS clients had the highest health sector costs overall, and the highest mental health ambulatory, inpatient, and antipsychotic medication costs specifically. NGO clients had the highest other sector costs overall and the highest NGO assistance, supported employment, and supported accommodation costs. Recent PSMHS clients had the lowest productivity losses for reduced participation and the highest costs for absenteeism and presenteeism. Conclusions: The costs of psychosis are broad ranging and very high. Development and implementation of cost-effective prevention, treatment, and support strategies is critical to maximizing the efficiency of service delivery. A needsbased framework based on principal service provider and recency of contact may facilitate this process. © 2014 The Royal Australian and New Zealand College of Psychiatrists.