This report describes the sampling and weighting methodologies for the 2013 Status of Forces Survey of Active Duty Members (2013 SOFS-A). The first section describes the design and selection of the sample. Because the questionnaire was divided into three modules, all participants were asked to complete Module A questions while half of the participants were randomly selected to complete Module B, and half of the participants were randomly selected to complete Module C. The second section describes the weighting and variance estimation procedures that were applied to the data. The final section provides response rates, including location and completion rates for the sample and for population subgroups after the data were analyzed.