As the power sector moves quickly toward decarbonization, authoritative research is demonstrating that a reliable transition that achieves economic, security, and climate goals is not only possible, but can be done at no more than – and possibly less than – the cost of “business as usual.” To achieve this, however, the discussion about market design needs to shift from traditional notions to a focus on what kind of investment will most efficiently complement production from a growing share of variable resources. This paper, which follows from an earlier collaboration between RAP and Agora Energiewende for the European Pentalateral Energy Forum, is the latest in a series of RAP papers on how market design can efficiently facilitate the transition to a clean power sector. It points out that the debate over energy-only versus energy-plus-capacity markets, while important, misses the point to some extent. What is needed is a more comprehensive discourse about how to optimize the mix of market instruments, governance, and regulation to best capture the need for an increasingly flexible system – ensuring that low-carbon reliability solutions can be implemented at reasonable cost.