This report documents the methodological procedures and evaluations of the 2008/09 Baccalaureate and Beyond Longitudinal Study (B&B:08/09). RTI, with the assistance of MPR, conducted B&B:08/09 for the National Center for Education Statistics (NCES) of the U.S. Department of Education. Chapter 1 describes the background, legislative authorization, and schedule and products of B&B:08/09. Chapter 2 presents the sampling details of the B&B:08 cohort and provides the definition of a B&B:08 cohort study respondent. Chapter 3 describes the development of the student interview and details of the data collection and results, and provides an evaluation of the student interview data quality. Chapter 4 describes the transcript data collection including systems for collecting, recording, and evaluating transcript data. Chapter 5 summarizes the file preparation process for the B&B:08/09 student interview and transcript data collections. Finally, Chapter 6 provides information pertaining to the weighting and variance estimation procedures for B&B:08/09. Materials used during the full-scale student interview and transcript data collection are appended to the report and cited in the text where appropriate. Appendices include: (1) NPSAS:08 Institution and Student Sampling Details; (2) Technical Review Panel; (3) Data Elements for Student Interview; (4) Facsimile of Full-scale Instrument; (5) Interviewer Training Agenda and Training Manual Contents; (6) Notification Material for Student Interview Data Collection; (7) Training Agendas for Transcript Data Collection; (8) Notification Material for Transcript Data Collection; (9) Data Elements for Keying and Coding System; (10) Imputation Rates; (11) Analysis Variables; (12) Design Effects; and (13) Nonresponse Bias Analysis.