If you want to supplement your Medicare Part A and Part B benefits, you can buy Medigap plans. Medicare Part a is free for most people, for Part B you have to pay a premium. For Medigap also you have to pay a monthly premium along with what you pay for Part B. Medigap plans are sold only by private insurance companies.
There are ten Medigap plans with varying benefits and rates. However, the benefits for a particular plan will be same irrespective of the insurance carrier. The premiums for every plan varies dependent on the company you are buying from along with your age, location and health condition.The same plan with the same benefits will not cost the same with different companies.
Apart from the monthly premiums, you also have to pay some deductibles and co-payments with some Medigap plans. For a doctor visit, usually the Medigap company will collect your Medicare Part B and sometimes Part A coverage information and pay the provider their share accordingly.All providers who accept Medicare also accept Medigap. You can give directions to the Medigap insurance company to pay the provider directly if they do not do so on their own.