Volume 48 | Number 6pt1 | December 2013

Abstract List

Valerie A. Lewis Ph.D., Carrie H. Colla Ph.D., Kathleen L. Carluzzo, Sarah E. Kler, Elliott S. Fisher M.D.


The Accountable Care Organization () model is rapidly being implemented by Medicare, private payers, and states, but little is known about the scope of implementation.


To determine the number of accountable care organizations in the United States, where they are located, and characteristics associated with formation.

Study Design, Methods, and Data

Cross‐sectional study of all s in the nited tates as of ugust 2012. We identified s from multiple sources; documented service locations (practices, clinics, hospitals); and linked service locations to local areas, defined as artmouth Atlas hospital service areas. We used multivariate analysis to assess what characteristics were associated with local presence. We examined demographic characteristics (2010 merican Community Survey) and health care system characteristics (2010 Medicare fee‐for‐service claims data).

Principal Findings

We identified 227 s located in 27 percent of local areas. Fifty‐five percent of the population resides in these areas. ‐level characteristics associated with presence include higher performance on quality, higher Medicare per capita spending, fewer primary care physician groups, greater managed care penetration, lower poverty rates, and urban location.


Much of the population resides in areas where s have been established. formation has taken place where it may be easier to meet quality and cost targets. Wider adoption of the model may require tailoring to local context.