The Railroad Retirement Board's Bureau of Actuary should improve its documentation of the sampling employed in the Financial Interchange process by: Creating a single document that explains the process used to create the sampling frame and sample, including source database(s) used, the variables of interest, and the programs/media used to execute the process steps. The documentation should be written such that a person with the requisite skills, but without knowledge of the Financial Interchange calculations, could understand and replicate the sampling process.