If you have Medicare, you should keep it. In fact, companies that sell Marketplace plans are prohibited from selling these plans to you if they know you are covered by Medicare. If you do drop Medicare and choose to re-enroll later, you can only re-enroll during the Medicare general enrollment period (from January 1 to March 31), and your coverage would not begin until July of that year, meaning that you would have a gap in coverage. You also may face a penalty for late enrollment in Medicare Part B and Part D. If you don’t sign up for Part B when you’re first eligible or if you drop Part B and then sign up again later, your monthly Part B premium may go up 10% for each year that you could have had Part B, but didn’t. You may also owe a late enrollment penalty for Part D drug coverage, which is equal to 1% of the national average premium amount for every month you didn’t have coverage as good as the standard Part D benefit.