The key for health insurance under 65 is that you have to establish a relationship with a primary care physician (or clinic) in the state where you have insurance and return for annual checkups if you have maintenance meds. Then if you become sick/injured it is an emergency situation and all PPOs that I have seen cover emergency treatment outside of coverage area. And if you use 'network' physicians (like BCBS) then costs are usually the same as it is when in your coverage area.
Barb