The "transaction rule" discussed in this article generically denotes a factually driven joinder requirement that might range in scope from the conduct formula embraced in Grady v. Corbin to a sweeping mandate that prosecutors include all joinable offenses "which substantially overlap" in a single indictment. One section of this article considers the sources of repeat prosecution in the Federal arena, the impact of the Federal sentencing guidelines on prosecutorial charging behavior, and the costs traditionally attributed to successive prosecution. Another section examines the arguments in favor of and against a statutorily imposed compulsory joinder approach, questioning whether either the definitional uncertainties of a transaction rule or the political benefits of the current approach are worth the individual and systemic costs inherent in an unchecked reprosecution power. The concluding section offers preliminary observations on issues that must be resolved if compulsory joinder of any variety is to succeed in the Federal environment. The author concludes that the implementation of a compulsory joinder regime will require intricate policy choices about the way Federal prosecutors do business, the courts' role in evaluating prosecutorial judgments, sentencing policy, and a myriad of other questions. Expanding the traditional transaction- rule debate to include such policy considerations may yield a rule that avoids "hamstringing" the prosecution, while adequately protecting defendants from government abuse of power. 199 footnotes