42 C.F.R. § 110.84
Upon payment of benefits under this Program, the Secretary will be subrogated to the rights of the requester and may assert a claim against any third-party payer with a legal or contractual obligation to pay for (or provide) such benefits and may recover from such third-party payer(s) the amount of benefits paid up to the amount of benefits the third-party payer has or had an obligation to pay for (or provide). In other words, the Secretary may pay benefits before the requester receives a payment from a third-party payer in certain circumstances. In those circumstances, the Secretary has a right to be reimbursed by the third-party payer. The circumstances in which the Secretary may assert this right include those in which the Secretary pays benefits under this Program to a requester before a final decision is made that a third-party payer has an obligation to pay such benefits to the requester. Requesters receiving benefits under this Program (or their representatives) shall assist the Secretary in recovering such benefits. In the event that a requester receives a benefit from a third-party payer after receiving the same type of benefits from the Secretary under this Program, the Secretary has a right to recover from the requester the amount of the benefit(s) received. The requester must notify and reimburse the Program within ten business days of receiving the third-party payment(s).
42 C.F.R. § 110.84