Most of those ads are for Medicare Advantage plans which promises bells and whistles ($0 premium, part B premium reimbursement, etc. etc.) but there are hoops to jump through to get them that they don't tell you. If I needed, say, an ablation and the nearest place I can have it performed under my policy's schedule is in, say, Charlotte, N.C., I'd have to drive there to get it. And it would have to pre-approved before the advantage plan paid for it. As such, I have a supplement plan that is taken anywhere Medicare is. I had an MRI last December that cost $2650. My co-pay: $50.