The history of payment reform models in healthcare primarily revolves around a shift from traditional fee-for-service payment, where providers were reimbursed for each individual service performed, to more value-based models that incentivize quality of care and improved patient outcomes, with a major turning point occurring in the 1980s with the introduction of the prospective payment system (PPS) using Diagnosis Related Groups (DRGs) for hospital reimbursements under Medicare; this was followed by further advancements through the Affordable Care Act (ACA) and the creation of the Center for Medicare and Medicaid Innovation (CMMI) which actively tests and promotes new payment models focused on value and quality.