While the Affordable Care Act’s coverage reforms attracted the most public attention, delivery system reform—through the implementation of risk-based payment and value-based care models—was a major component of the legislation as well. In particular, the Obama administration hoped to use the evolution of Medicare reimbursement as a means to incentivize broad-based transformation across payer and provider segments, ultimately inflecting the rate of health care spending growth in the United States.

Ten years after the passage of the ACA, adoption of risk-based payment models has been both slower than expected as well as highly variable across payersegments. Despite the ACA’s focus on Original Medicare reimbursement, Medicare Advantage has actually achieved the highest levels of adoption, with over 50% of its payments funneled through shared-risk or population-based models, followed by Original Medicare at about 40% of its payments. The Medicaid and commercial segments lag far behind.