First of all, states regulate insurance. In most states, you can only purchase health insurance from a small number of state regulated companies. One proposal to reduce insurance costs is to allow health insurers provide services across state lines -- like home and auto insurance! For example, in my home state of Washington, the insurance commision essentially allows only 4 companies to dominant >90% of the market. Why shouldn't I be able to purchase a policy from a lower cost provider in Indiana?
This is spin. The big carriers like BC/BS and United operate across the country. They are, however, incorporated in individual states and required to operate within the laws of those individual states. The movement to "allow" insurers to provide services "across state lines" is really nothing more than an attempt at eliminating states' regulation of the insurance industry. Ironically, the proponents of this idea cry out for state's rights on most other issues. It might result in some efficiencies that might reduce costs, or it might not. But it's not about the rights of small regional insurance providers to do business in the next state and it never has been.
Tim