There are hundreds of companies that offer Medicare Supplement plans. They are all regulated by Medicare and licensed by the state in which they offer plans. You may recognize big name companies since they have large advertising budgets. But, it doesn’t mean they have the lowest rates. The rating of the company is not as important as other factors such as how long they have been offering Medicare plans and also their rate increase history. You don’t have to worry about whether the company will pay all the bills. All claims go to Medicare FIRST and Medicare determines whether to approve the claim, not the insurance company (like other types of health insurance). If Medicare approves the claim they tell the insurance company to pay. They all pay claims the same way, they have to it’s the law. Also, if a company were to go out of business for whatever reason, you are protected in that you have a guaranteed right to get the same plan from another company in your area.