This publication describes the methods and procedures used for the 2008/18 Baccalaureate and Beyond Longitudinal Study (B&B:08/18). The B&B graduates, who completed the requirements for a bachelor's degree during the 2007-08 academic year, were first surveyed as part of the 2008 National Postsecondary Student Aid Study (NPSAS:08), and then followed up with in 2009 and 2012. The 2018 follow-up is the third and final survey for the B&B:08 cohort, conducted 10 years after completion of the bachelor's degree. This report details the methodology and outcomes of the B&B:08/18 student survey data collection and administrative records matching. [For "Baccalaureate and Beyond (B&B:08/18): First Look at the 2018 Employment and Educational Experiences of 2007-08 College Graduates. First Look. NCES 2021-241," see ED609932.]