Feb. 20—A total of 428 accountable care organizations (ACOs) existed nationwide at the end of January 2013, with the growth in ACOs extending beyond the Medicare Shared Savings Program, according to research in a Health Affairs blog post.

More than 250 of the 428 ACOs are Medicare Shared Savings Program ACOs. The remaining ACOs have originated from the private sector. According to the research, physician groups have surpassed hospital systems as the backers of the greatest number of ACOs, although the physician-led entities tend to be smaller than those led by hospitals. 

Today, ACOs exist in 49 states, Washington, D.C., and Puerto Rico. ACO growth has spread extensively in the Midwest and on the West Coast, as well as in population centers such as the Northeast. According to the research, the least growth has occurred in portions of the Deep South, the Great Plains, and the western mountain areas.

California, Florida, and Texas lead the nation with 46, 42, and 33 ACOs, respectively, according to the research. And ACOs are present in nearly 80 percent of the 306 hospital-referral regions—geographic regions defined by the Dartmouth Institute for Health Policy as representing markets where patients are likely to be referred for tertiary care.

Health insurance companies continue to provide financial backing and a willingness to explore different payment models, as opposed to sponsoring ACOs, the research found.

Publication Date: Wednesday, February 20, 2013