Thanks for added info. I live in MN and recall on TV last year the comment that a MN insurance company has a hard sell if they do not offer Mayo Clinic as a provider. So there were some agreements made with Mayo. But even for those exceptions, Medicare Advantage plans change every year (they even tell you to call because of that in their advertsing!) so one never knows where one will end up.
Having worked in Corporate America I understand business models. Advantage Plans must create a network of providers who agree to take less than the balance of 20% from Medicare established cost for a procedure. And why do doctors do that? To get guaranteed patients and they have the interest to see as many as possible in any given time frame. And the insurance company has the interest to discourage patients from utilizing benefits. Medicare does not need to advertise, and it utilizes a set of codes across the country while these independent insurance companies must set prices each year with all their providers, and they must advertise and advertise so right off the bat they have much higher operating costs which have no benefit to you and me! And look at the extra costs providers have because they must hire people to administer so many different insurance plans.
We need quality affordable healthcare. That requires clear objectives and competent people to design and administer. That should not be hard to do. Medicare is actually quite cost effective