Specialized Medicare supplemental insurance policy whose predefined minimum benefits are regulated by the federal government and devised for the Medicare beneficiary. It typically covers the deductible and copayment amounts not covered under the Medicare policy. This coverage is available only to individuals who are covered by Medicare and is purchased by individuals or by employers to cover retired employees. Except in Massachusetts, Minnesota, and Wisconsin, there are 12 standardized plans labeled Plan A through Plan L. Medigap policies only work with the Original Medicare Plan. Also known as complementary program, gap fill, Medifill, Medicare supplement policy, Medsupp, Medicare wrap, supplemental health insurance , or wraparound plan .