The growing prospect of comprehensive national climate change legislation raises many important questions about the role of state efforts in a national climate change program. This article identifies the key state/federal issues that should be addressed in any comprehensive national comprehensive climate change legislation. It also provides recommendations for resolving these issues. In addition to a cap-and-trade program and uniform national standards for some sectors, federal climate change legislation should adopt and modify the State Implementation Plan model in the Clean Air Act. That is, states should be given responsibility through State Implementation Plans to achieve specified emissions reductions, including those from electricity demand reduction.