The number of accountable care organizations and alternative payment models is growing, as is the number of people served by such programs.

According to a new study published on the Health Affairs Blog, there are more than 900 ACOs across the country – a 10 percent increase over a year ago.

32 million Americans are served by ACOs today – 2.2 million more than a year ago.  Among them, 59 percent are served through commercial contracts, 29 percent by Medicare contracts, and 12 percent under Medicaid contracts.  ACO growth is greatest in metropolitan areas, the states with the greatest ACO penetration are Rhode Island and Maine, and the states with the least ACO penetration are Wyoming and West Virginia.

Among alternative payment models, growth is greatest among shared-savings and shared-risk ACOs, include episode-based models and partially- and fully-capitated payments for patient populations.  Today, APMs account for more than 30 percent of Medicare payments, with the greatest number, by far, participating in Medicare’s Comprehensive Primary Care Plus Model, followed by Medicare’s Comprehensive Care for Joint Replacement and Shared Savings Program models.

Learn more about the growth of ACOs and APMs, the current policy environment for such approaches, and possible future changes in these approaches in this Health Affairs Blog article.