When Medicare has determined that an overpayment has occurred, a Demand Letter is issued. Providers are given 30 days from the date of the Demand Letter to pay the requested overpayment amount. Timely payment is needed to avoid interest from accruing. The Demand Letter includes detailed information necessary to satisfy the overpayment and information on how to submit an appeal if there is a disagreement with the overpayment. The Demand Letter will also be assigned a Letter Number which is used to identify what has been demanded by Medicare. If the provider disagrees with the overpayment decision, an appeal may be filed. An appeal is an independent review separate from the review of the initial determination. The first level of an appeal is a redetermination. A redetermination request must be filed within 120 days from the date of the Demand Letter. However, to avoid recoupment from occurring, the redetermination must be filed within 30 days from the date of the demand letter.