(1) The department or self-insurer may adjust payment of charges when appropriate. The department or self-insurer must provide a written explanation of why they adjusted a billing or line item of a bill when they make any adjustment. In cases where the department is the referral source, it will not give the provider a written explanation if the department made the adjustment solely to conform to its maximum allowable fees.

(2) The department or self-insurer must receive any inquiries about a bill adjustment within ninety days from the date of payment to be considered. All provider inquiries must be in the required format.