I am using Obamacare from January to June of this year, my birthday is in June, how do I cancel Obamacare and go on to Medicare when I am 65?
If you have a Marketplace plan through ObamaCare, you'll keep it until coverage starts. Then you can cancel your Marketplace plan, or keep it.
The only thing to be aware of is if you’ve been getting premium tax credits or other savings on a plan you bought through the Marketplace, these savings will end once your Medicare Part A coverage starts. So you’d have to pay full price for the Marketplace plan.
Don't enroll in Medicare late to keep an Obamacare plan: If you enroll in Medicare after your initial enrollment period ends, you may have to pay a late enrollment penalty for as long as you have Medicare. In addition, you can enroll in Medicare Part B (and Part A if you have to pay a premium for it) only during the Medicare general enrollment period (from January 1 to March 31 each year). Coverage doesn’t start until July of that year. This may create a gap in your coverage.
Learn more about Medicare and the Marketplace.