In January and February 2015, Urban Institute researchers released three papers analyzing the implications of a Supreme Court ruling for the plaintiffs in King v. Burwell. A finding for the plaintiffs would eliminate the premium tax credits and cost-sharing reductions currently being provided under the Affordable Care Act in the states where the federal government is playing a role in operating the new nongroup insurance marketplaces established under the law. The Heritage Foundation criticized the validity of some of these estimates, as well as related analyses released by other researchers. Here the UI researchers respond to each of these criticisms.