There are many rules surrounding your initial enrollment into the world of Medicare. Unless you have an illness or disability that has made you Medicare eligible early, or you are still working and using the health insurance from your company as your supplement, your initial enrollment window will start 3 months before your 65th birthday and will continue through the 3 months after you turn 65. During this period, you’ll be able to purchase the supplemental policy of your choice. However, once this period closes, if you wish to change supplements, you will, most likely, be subject to underwriting and could be denied.
You should always consult with a professional to determine your eligibility for different coverage before you cancel your current coverages.