not sure what is offered, but in order to be accepted everywhere, you need to look for a PPO or EPO plan. These plans don't require a primary care physician and usually do not require referrals for specialists, etc.
We have an EPO plan, which is the less expensive of the two, that only requires we choose only an "in network" physician/facility. The PPO that we had prior to this allowed us to go out of network and pay higher premiums. We changed to the EPO because after eight years we never had a problem in any state finding an "in network" provider...our plan is BCBS.