With many European Energy Union discussions focused on securing energy supplies first, RAP recommends “Efficiency First” as an organizing and decision-making principle—an approach that has been adopted in California and elsewhere in the United States in various forms over the last two decades. At an Energy Efficiency Alliance Meeting sponsored by the European Climate Foundation, Meg Gottstein explored the lessons learned from U.S. experience in “getting to Efficiency First.” Drawing from experience in California and other states, she identifies key questions regulators should explore when developing and implementing Efficiency First principles, along with examples of “do’s and don’ts” for legislating prescriptive, detailed requirements for efficiency programs.