42 CFR §424.90

1. (a)Conditions for acceptance. An assignment or reassignment established by or in accordance with a court order is effective for Medicare payments only if—
   1. (1)Someone files a certified copy of the court order and of the executed assignment or reassignment (if it was necessary to execute one) with the intermediary or carrier responsible for processing the claim; and
   2. (2)The assignment or reassignment—
      1. (i)Applies to all Medicare benefits payable to a particular person or entity during a specified or indefinite time period; or
      2. (ii)Specifies a particular amount of money, payable to a particular person or entity by a particular intermediary or carrier.
2. (b)Retention of authority to reduce interim payments to providers. A court-ordered assignment does not preclude the intermediary or carrier from reducing interim payments, as set forth in § 413.64(i) of this chapter, if the provider or assignee is in imminent danger of insolvency or bankruptcy.
3. (c)Liability of the parties. The party that receives payments under a court-ordered assignment or reassignment that meets the conditions of paragraph (a) of this section and the party that would have received payment if the court order had not been issued are jointly and severally responsible for any Medicare overpayment to the former.