If you’re turning 65 or enrolling in Medicare for the first time, the decisions you make now can impact your healthcare—and your wallet—for years to come. Unfortunately, many people make simple mistakes that end up costing them thousands of dollars in unnecessary expenses, penalties, or coverage gaps. The good news? Every one of these mistakes is avoidable—if you know what to look for. Let’s walk through the most common (and costly) Medicare mistakes in 2026. Mistake #1: Miss