Looking into resources offered by AARP is a good idea, @wessells.

I found this place to help people get started:
- Health Care and Coverage (AARP) https://www.aarp.org/health/health-insurance/

You have traditional Medicare, with good Medigap policy. So do I and at MC Rochester I never saw a bill - and I had both VAT surgery and a cardiac stent done. The comment above about insurance regulations being different by State is interesting. We are lucky in Minnesota. I did read that Mayo Arizona handles things differently.
One thing did happen though with billing - I originally had emergency angiogram done in Twin Cities and they identified blockage. I refused stent because I knew I had something wrong with my lung/upcoming Mayo appointment and I ALSO KNEW a stent requires blood thinning treatment for 6-12 months and nobody would want to operate on me while I was on Plavix. So, they put me on medication for the coronary blockage until I could resolve the lung issue. A few weeks later I had lung surgery, and they removed a stage 1b cancer. I MADE THE RIGHT CALL!!!! I was nervous about refusing the stent but they did tell me that research shows one can manage on medication and not a stent for CAD. With my type of lung cancer, I know that surgery could be a possibility in the future, and I did not want to compromise my treatment options. So, I asked for a consult at Mayo on whether given my blockage characteristics, it was better for me to stay on medication or do a stent. Unfortunately, when they did the angiogram in Minneapolis, they did not do any measurements about blood flow and that would be key to the decision (many places do not take this measurement). Mayo suggested a blood measure CT scan test, put it in the system and Medicare refuses to cover it. WHAT?? Cost $11000, NO I am not going to pay that. Mayo then recommended I do another angiogram with blood flow measurements and make decision on that. That is of course more invasive, but I do it and actually they do decide on a stent. Now I did a little googling and found guidelines about when to do this CT blood flow test. I suspect that the reason Medicare did not want to cover that test was because I had already done an angiogram 4 months before showing severe blockage.