Medicare Advantage Plans are a type of Medicare health plan offered by a  private company that contracts with Medicare to provide all your Part A  and Part B benefits. Most Medicare Advantage Plans also offer  prescription drug coverage. If you’re enrolled in a Medicare Advantage  Plan, all Medicare services are covered through the plan. Your Medicare  services aren’t paid for by Original Medicare.  

 The best time to buy a Medigap policy is during your 6-month Medigap  Open Enrollment Period. You generally will get better prices and more  choices among policies. During that time you can buy any Medigap policy  sold in your state, even if you have health problems. This period  automatically starts the month you're 65 and enrolled in Medicare Part B (Medical Insurance),  and it can't be changed or repeated. After this enrollment period, you  may not be able to buy a Medigap policy. If you're able to buy one, it  may cost more due to past or present health problems. 

 The late enrollment penalty is an amount added to your Medicare Part D  monthly premium. You may owe a late enrollment penalty if, for any  continuous period of 63 days or more after your Initial Enrollment  Period is over, you go without one of these.