42 CFR §405.946

1. (a)Evidence submitted with the request. When filing the request for redetermination, a party must explain why it disagrees with the contractor's determination and should include any evidence that the party believes should be considered by the contractor in making its redetermination.
2. (b)Evidence submitted after the request. When a party submits additional evidence after filing the request for redetermination, the contractor's 60 calendar day decision-making time frame is automatically extended for up to 14 calendar days for each submission.