Introduction In March 2010, President Barack Obama signed the Affordable Care Act into law, expanding health insurance coverage to millions of previously uninsured Americans. In addition to coverage expansions, the ACA also includes numerous provisions that promote a shift toward value-based reimbursement, the creation of new models of care (e.g., patient-centered medical homes and accountable care organizations), and funding to test new strategies to improve quality, reduce costs, and improve the patient experience of care. The reforms in the ACA accelerate the pace of transformation, but even absent government-mandated reform, the many forces outlined in this chapter will compel the inevitable transformation of the U.S. health care system.