McClarren-Ferguson prohibits the federal government from interfering in the "business of insurance". That regulation of insurance companies are the exclusive bailiwick of the states. Even though insurance companies may do business in many states, they have to follow the regulation by the individual states. That's why one can not buy an insurance policy issued in a state where one does not reside. In otherwords, if you want to buy an auto or a health or any kind of policy, you must buy it from the company that is doing business in your state from an agent of that company in your state. The commerce clause does not apply in this instance.
