Four insurers have been named the best Medicare Part D carriers for 2025 by U.S. News & World Report. U.S. News consulted with Medicare experts to determine the important factors for those enrolling in a Part D plan and assigned a weight to each measure. Those weights were then applied to CMS data. The final rating includes companies that earn a score of at least 3 out of 5 total or higher and have at least 1,000 enrollees per state in at least 10 states. The full methodology is here.