Medicare supplement plans or Medigap is the private health insurance plans that are for those people who already have a Medicare policy. The Medigap or Medicare supplement plans helps the Medicare beneficiaries to bear that extra medical cost that are left aside by the original plans. The name Medigap is suggested because it is believed that these policies bridges the gap between the Medicare coverage and the original expenses or the total bill charged.If you are in the Original Medicare plan you are able to buy a Medicare supplement plan and both of them would pay you their share of coverage. It is to be noted that the Medigap policies are private health insurance plans and the private insurance companies can only sell them and not by any government organizations. These plans are totally administere hr support for small businesses d by the private insurance companies. But it is to be mentioned that though these plans are completely administered and sold by private insurance companies but still there are only 12 supplementary plans labeled A through L. All these plans have there separate policy coverage but the plans under the same letter cover must provide the same benefits. It means that no matter from which company you have bought the policy, they must provide the same coverage as provided by the other companies, nothing more or nothing less.Almost all of the Medicare Supplement Plans provide the basic benefits of plan A and in addition to that they have their additional benefits. Therefore before choosing a plan for yourself you need to be very careful so that you may choose the right one for yourself and not loose the deal.