I am over age 65 and covered by Medicare, but I’m wondering if I can purchase one of the health plans offered through the Marketplace and drop my Medicare coverage? Is that an option for me or should I keep my Medicare?

If you have Medicare, you should keep it. Companies that sell Marketplace plans are prohibited from selling these plans to you if they know you are covered by Medicare (this applies even if you have a Medicare Advantage plan, a Medicare Part D prescription drug plan, or a Medigap policy).