File a Medicare complaint or grievance
Not every problem is an appeal. If something was denied, reduced, or ended, that's an appeal — see how a Medicare appeal works. If it's about how you were treated, the quality of care you received, or your plan's service, that's a grievance or complaint — free, and handled here.
Your plan is supposed to tell you which track your issue belongs on — but plans get this wrong often enough that it's worth checking yourself.
Is this about a decision, or about how you were treated?