I have a Medicare Advantage plan through Kaiser Permanente. They call it their Senior Advantage Plan. It is excellent and consistently rated top in its class here on the West Coast. I love it.
Only problem is, Kaiser is pretty much only in California, Oregon, and Washington State. There is a sliver of Kaiser running through Northern Virginia into Maryland, I seem to recall. They may be in Hawaii. But that's about it.
Kaiser is top-notch. You must work within their system, but they have EVERYTHING. It is truly amazing. For instance, when my physician thought I should consider nasal surgery, I had an appointment with the surgeon the following week. And then the surgery was about one week later. No paperwork to fill out. No permissions needed. No carrying X-rays back and forth. Nothing.
It is a seamless operation. Doesn't matter what I need: MRI, CT scan, ER, surgery, ..., whatever I need, I get. And I never have to fight to get what I need.
Kaiser is the one Advantages plan that has it right. Unfortunately that is not the case for most of them. Especially if you live in a rural community. We have 2 choices for Advantage plans and many of our local Drs no longer accept the insurance.