Ensuring that there is adequate generation to meet established reliability standards is an imperative task for regulators. In organized wholesale markets, however, how exactly to ensure medium- to long-term resource adequacy continues to be the subject of debate and experimentation. Different jurisdictions have adopted different responses, with several markets mandating the procurement of capacity through organized capacity markets. Although the existence and operation of the capacity markets varies across jurisdictions, persistent concerns remain about the functioning and adequacy of capacity markets to ensure long-term reliability—especially in light of a rapidly changing grid with higher penetration of variable renewables and distributed energy resources. This session is part of the Electricity in Transition series from the Energy and National Security Program and will cover the basic theory behind capacity markets, discuss the pathways different jurisdictions have pursued, as well as the challenges perceived by states and market participants. It will also focus on how resource adequacy mechanisms may need to change to respond to the changing generation mix, the goal of decarbonization, and the integration of distributed energy resources.