The development of accountable care organizations (ACOs) in the United States has created a climate where the financial success of an entire provider network depends on each physician pulling his or her weight, creating considerable pressure to perform. The use of ACOs in Medicare is still at an early stage, with the launch of 88 new ACOs in July bringing the total number to 153.1 However, the developments and challenges experienced by the 221 organizations already operating as ACOs in the commercial health sector can provide insights into how they affect physicians.2

The fundamental ethos of an ACO is that the contracted providers are eligible to share in a proportion of any savings made in the cost of provision, on the condition that certain quality standards are met. To achieve the intended cost savings, ACO providers typically work together to develop a care management approach targeted at patients at risk of potentially avoidable admissions or emergency department visits. Such care management is either preventive (proactively contacting patients with a high risk profile and deriving a community based care plan) or reactive (care coordinators based in a hospital intercept patients and direct them to other resources).