In the ever-evolving landscape of healthcare policy, the Inflation Reduction Act (IRA) of 2022 initiates significant changes aimed at curbing prescription drug costs and reshaping Medicare Part D. Signed into law by President Biden on August 16, 2022, the IRA’s provisions are set to transform the Medicare Advantage (MA) landscape, particularly through a significant restructuring of the Part D benefit design slated for 2025. This brief delves into the profound implications of the IRA on MA plans and Accountable Care Organizations (ACOs), illuminating the complex interplay between policy reforms, plan dynamics, and provider risks.