Medicare Supplement (Medigap) Plans fill the gaps that Original Medicare doesn’t cover. A variety of plans are available to pay deductibles and coinsurances and provide additional coverage for long-term hospital stays once you exhaust your lifetime reserve days. If you enroll in one of these plans within six months of first becoming eligible for Medicare Part B, you are guaranteed acceptance into any Medicare Supplement plan offered in your area. After this guaranteed enrollment period, you may be required to answer medical questions, and you may be denied coverage. So, if a Medicare Supplement plan is right for you, sign up during that period even if you are healthy at the time you are first eligible. If you wait until your health deteriorates, you may not be able to purchase a Medicare Supplement plan, or you may have to pay much more for it.