How Do Medigap Plans Work? 
Medigap policies serve as a supplement to Original Medicare . Original medicare is an 80/20 plan , where Medicare pays 80 % of the approved charges . The beneficiary is typically responsible for the 20 % co-insurance as well as co-pays and deductibles that come with Medicare Parts A & B . The Medigap policy is designed to pick up the 20 % Medicare does n't cover in exchange for a monthly premium payable to the carrier selected . The most comprehensive Medigap policy is Plan F , which covers all of the Part A & B deductible , co-insurance and co-pays , so when the beneficiary goes to receive care their is zero out-of-pocket costs . Some plans may also provide benefits like foreign travel as well as a gym membership as part of your regular plan . Please note : when purchasing a Medigap Policy , you need to add a Stand-Alone Prescription Drug Plan to satisfy your requirement as a Medicare Beneficiary to have Part D - Prescription Drug Coverage met . 