I'm unhappy with how my Medicare plan treated me. Do I file a complaint or an appeal, and where?

Medicare.gov says to file a complaint, also called a grievance, for two kinds of problems. One is the quality of your care. The other is how your plans treat you [1]. File an appeal if a plan refuses to cover a service, supply or prescription. File an appeal too if you got a bill for a claim you already sent in [1].

Where to go depends on the problem. For your Medicare health or drug plan, use the Medicare Complaint Form or follow your plan's papers [1]. For the quality of care from any provider, contact the BFCC-QIO, a Medicare quality group [1]. For nursing home or unsafe facility conditions, contact your State Survey Agency [1]. For a doctor's licensing or conduct, contact your State medical board [1].

For Medicare health plans, CMS says an enrollee must file a grievance, verbally or in writing, no later than 60 days after the triggering event [2]. The plan must notify you of the result no later than 30 days after it gets the grievance. If the plan extends that time in the enrollee's best interest, it can add up to 14 calendar days [2].

Open Medicare.gov, Filing a complaint, at https://www.medicare.gov/providers-services/claims-appeals-complaints/complaints and read the part quoted above. Source 2 lists another page to open. Your own plan or policy papers hold details these sources do not give: "Don't know yet" for your case.