CMS states that a level 1 redetermination generally must be filed within 120 days after receipt of the initial determination, but the MSN gives the date and destination for the specific claim.
How the general rule works
CMS presumes that the initial determination was received 5 calendar days after the date on the notice unless there is evidence showing a different receipt date. Because the MSN already provides an appeal deadline, use that printed date rather than calculating a new one yourself.
What if the deadline has passed?
You may still submit a written redetermination request and explain why it was late. Medicare states that a late appeal may receive a decision when there is good cause for missing the deadline, such as an illness, disability, or accident that delayed filing. The contractor decides whether the facts establish good cause, so include a specific explanation and any useful supporting information.
When this answer does not apply
This 120-day rule concerns a standard first-level appeal of an Original Medicare claim determination. Medicare Advantage plans, other Medicare health plans, and Medicare drug plans use their own notices and appeal timeframes. Fast appeals involving current hospital, skilled nursing, home health, hospice, or rehabilitation services can have much shorter deadlines. Follow the notice immediately.
Action to take
Locate the last page of the MSN, note the appeal date and MAC address, gather the claim details and supporting information, and submit the written request with enough time to keep proof of delivery.