Hi Sam,
I’m wondering if there was a miscommunication with Mayo about them accepting you as a patient with Medicare as your only insurance.
Not necessarily the same, but I had a 2019 biopsy at Mayo and Jan/Feb 2020 PBT (Proton Beam Treatment) at Mayo. My primary coverage was Medicare and my secondary a policy from my wife’s retirement (good coverage). That said, our secondary starts at 80% of the 20% that Medicare doesn’t cover. I had tiny bills related to my treatment.
Don’t know if it might be the type of treatment would make a difference. Not long ago many insurers were not covering PSMA/PET scans and its my casual impression that now most insurers cover the PSMA/PET scans.
I wouldn’t stop with the first “No”.
Good Luck