The Institute of Medicine (2013) highlights several key opportunities for US healthcare delivery system improvement, including the following:

* “50% of patients report that information needed for care delivery was not available when it was needed;
* 25% of patients said their providers have to re-order tests to have accurate information for diagnosis;
* Over 1/3 of inpatients are harmed during their stay, while 1/5 of Medicare patients are readmitted within 30 days;
* 50% of patients with a chronic condition report that diagnosis and treatment information is not available when needed;
* Less than 50% of patients receive clear information on the benefits and trade-offs of treatments;
* Almost 50% of patients are unsatisfied with their level of control in medical decision- making;
* 1/3 of health care expenditures, or roughly $750 billion, do not improve health” (p.1).
Provider organizations are increasingly responding to the aforementioned pressures and health care system reforms by forming ACOs or shared-savings and risk contracts.ACOs are growing steadily. By 2014, a recent study reported there were 522 Medicare ACOs, serving 15 to 17 percent of the US patient population, representing an increase of nearly 43% compared to 2013 levels. Surprisingly, these Medicare ACOs are also serving an approximate 33 million non-Medicare beneficiaries. The same study also found about 155 non-Medicare ACOs in operation, a 14% increase from 2013, serving between 9 million and 16 million patients. This growth is evident geographically also. The study found 67% of the US population lives in a primary care service area served by an ACO, with about 40% of the population living in a service area served by two or more ACOs (Gamble, 2014, p.1).