Medicare Part D catastrophic coverae

[nonekeep11]

I am trying to find a medicare Part D plan that would cover catastrophic events such as infusion or chemotherapy at oncologists office or very expensive brand name drugs in the event that that those services might be required down the line.I can afford to pay for most generic drugs with cash using goodRX .Are there medicare plan D that has a reasonable premium out there that someone would recommend?

We don't anticipate needing those treatment sbut just in case.

Thanks