DEFINITION of 'Medicare Supplementary Medical Insurance - SMI'
Health insurance sold by private insurance companies meant to top up an original Medicare plan. Medicare supplementary medical insurance, commonly known as Medigap, covers additional healthcare costs that may not be covered under the traditional Medicare plan, such as emergency room services and ambulatory surgical procedures.
BREAKING DOWN 'Medicare Supplementary Medical Insurance - SMI'
Medicare supplemental heath insurance has 12 standardized policies, categorized as plans A through L. Typically, when purchasing supplemental medical insurance, one must already be covered under Medicare A and B. In addition to any premiums associated with the original Medicare plan, subscribers must also pay premiums for any Medigap services they purchase over and above their original plan; however, as long as premiums are paid in good order, Medigap insurance policies are guaranteed to be renewed the following year.