This report examines the extent of quarterly transitions between services using data linked deterministically via the statistical linkage key SLK-581. Basic descriptive statistics are provided for those making these transitions. Data relating to the period 1 April 2002 to 31 March 2003 were used. As with all projects using statistical data linkage within the AIHW, data linkage was carried out following examination and approval by the AIHW Ethics Committee. A previous report, Data Linkage Protocols Using a Statistical Linkage Key (AIHW: Karmel 2005), examined the quality of the data available for undertaking statistical data linkage between the programs and described the protocols followed to ensure that the privacy of individuals was not compromised. Practices that allow consistent linkage procedures to be used over time and across data sets were also outlined.