The accountable care organization (ACO) is a staple of healthcare reform. CMS will launch its Shared Savings Program --- an ACO for Medicare patients --- in January 2012. John Harris, principal with the consulting firm of DGA Partners, advises potential participants in an ACO to lay the groundwork now. In this interview, he recommends eight elements of an ACO infrastructure and weighs in on the patient-centered medical home's role in an ACO. Harris is one of five contributors to "Essential Guide to Accountable Care Organizations: Challenges, Risks and Opportunities of the ACO Model," a 60-page resource that answers key questions surrounding ACOs so that hospitals, PHOs, IPAs and other physician organizations, networks or group practices can weigh the merits now of creating or joining an ACO before CMS's ACO launches next year.