I love plan F. It is easier to know what to pay than plan for the unknown. You can go to any doctor or specialist but you must ask if they accept Medicare assignment. That means that they accept what Medicare pays and your supplement picks up the rest of the bill up to what Medicare says is reasonable and customary. If they do not you will be responsible for any amount that they are charging over and above what Medicare and your supplement pays. They will accept the insurance amount but will bill you for any amount over what the insurance pays. Please PM me if you want to talk. This is my area of work.