HASI is a joint initiative between NSW Health and Housing NSW. The aim of the program is to provide stable housing and accommodation support for people with mental health issues in NSW. In 2002, Stage 1 of the program was rolled out in selected areas across NSW. It provided housing and access to high support services for 100 clients. A previous evaluation of HASI Stage 1 found that the initiative had a positive impact on individual clients in terms of improving mental health, providing stable housing and improving community participation (Muir et al. 2007). Since then, new stages of the HASI program have been introduced and the program now supports over 1,000 clients. The initiative has evolved to meet the different support needs of clients ranging from low, medium, high and very high support service levels. The overall evaluation questions are: 1. Participant outcomes: To what extent has the initiative met its objectives for individual clients? 2. Policy and service delivery model: How effective is the HASI service delivery model? 3. Economic analysis: What are the costs and benefits of HASI?