My Medicare Summary Notice shows a service as denied. Do I owe money, and what do I do?

Medicare.gov says the Medicare Summary Notice (MSN) is not a bill. People with Original Medicare get it in the mail at least twice a year [1]. It shows the services or supplies that providers billed to Medicare in that period. It shows what Medicare paid and the maximum amount you may owe the provider [1].

Medicare.gov gives these steps. Keep your receipts and bills and compare them to the MSN. If you paid a bill before you got the notice, compare the MSN with the bill to make sure you paid the right amount. If an item or service is denied, call your doctor's or other provider's office to make sure they sent the correct information. If they did not, the office may resubmit [1]. If you have other insurance, check whether it covers anything Medicare didn't [1].

If you disagree with a decision, you can file an appeal. The last page of the MSN gives step-by-step directions [1]. The federal rule says a request for redetermination must be filed within 120 calendar days from the date you receive the notice. The date of receipt is presumed to be 5 days after the date of the notice [2]. If that time has passed and you show good cause, the contractor may extend it. You ask in writing and say why you were late [2]. The sources here do not explain what each denial code on an MSN means. "Don't know yet" for your notice.

Open the Medicare.gov MSN page and compare it with your own notice, line by line. Your MSN shows your amounts and dates - "Don't know yet" from these sources.