In October 2014, AcademyHealth and the Robert Wood Johnson Foundation convened grantees and a diverse group of faculty to continue exploration of payment reform design and implementation issues. The grantees and national experts focused on two different topics: best practices in payment reform and new areas of payment reform development that push current boundaries. This brief summarizes three emerging challenges identified during the meeting that will need to be addressed to assure the long-term success of payment and delivery system reform. It also provides examples of current activity in each area and identifies issues for future exploration and strategy development.