In this article for the Journal of the American Medical Association (JAMA), Drew Altman and former U.S. Senate Majority Leader William Frist examine the roles the Medicaid and Medicare play in the health system today from the perspectives of the public and beneficiaries, providers, and policymakers, and discusses the challenges they face in the future. The article is accompanied by an audio interview with Altman and Frist, who is a member of the Foundation’s board of trustees.