From what I know about tax law, and it isn’t much, the Federal Government can’t impose different tax laws for different states.
Since Roberts has called the penalty a tax, it must be imposed to all citizens in all states in the same way. It would seem that this is impossible due to a difference in insurance set up and access in the states.
Therefore the ACA is unconstitutional based on the Roberts decision?
Same tax for each state. Use exchanges, get subsidy. Forego exchanges, no subsidy. As another said, it’s a carrot and stick approach: you don’t have to, but get rewarded if you do. Same options for all states. Just like other things like federal highway funds.