I recently read a Wall Street Journal article which explained the problem of interstate health insurance. It is currently prohibited to purchase health insurance coverage from a company in a state where you do not reside. This greatly reduces the number of options one has to secure the most cost effective plan. It would be impossible to obtain coverage by Select Med if I lived in New York.
Eliminating state boundaries would immediately increase competition which in turn would result in lower health insurance premiums. Increase the supply and the prices will fall. Competition is always a main driver for more affordable products and services. Let more companies fight for your business. Let pricing become a competition.
This is not a complete solution to the health insurance problem, but it will definitely increase its affordability.