Medicare Part B costs are increasing in 2026, and the changes matter for retirement cash flow planning because they affect both monthly premiums and out-of-pocket exposure before coverage begins. CMS has released the updated 2026 figures, including the standard Part B premium and the annual Part B deductible, along with key Part A hospital cost-sharing amounts. For many retirees, these updates become a practical budgeting checkpoint: premiums typically come out of Social Security or are billed directly, while deductibles and coinsurance shape how much “buffer” you may want in a healthcare spending plan. Understanding the updated numbers—and how they fit into a larger retirement income picture—helps reduce surprises as a new year begins.