Restricted-use data for waves 1-3 of BTLS were released in September 2011, and a combined waves 1-4 data file is expected to be released in the summer of 2012. The next collection of data, for wave 5, is scheduled to begin in January 2012. In the summer of 2013, about a year after the close of data collection, the restricted-use data file containing waves 1-5 will be released. Wave 5 will be the final wave for the 2007–08 cohort of BTLS. Research is being conducted on the 2011–12 SASS to determine the feasibility of launching a second cohort for BTLS from the 2015–16 SASS.