5 U.S.C. § 8131: Subrogation of the United States

assign to the United States any right of action he may have to enforce the liability or any right he may have to share in money or other property received in satisfaction of that liability; or prosecute the action in his own name. A beneficiary who refuses to assign or prosecute an action in his own name when required by the Secretary is not entitled to compensation under this subchapter. The Secretary may prosecute or compromise a cause of action assigned to the United States. When the Secretary realizes on the cause of action, he shall deduct therefrom and place to the credit of the Employees’ Compensation Fund the amount of continuation of pay or compensation already paid to the beneficiary and the expense of realization or collection. Any surplus shall be paid to the beneficiary and credited on future payments of compensation payable for the same injury. However, the beneficiary is entitled to not less than one-fifth of the net amount of a settlement or recovery remaining after the expenses thereof have been deducted. releases to the Panama Canal Company any right of action he may have to enforce the liability of the Panama Canal Company; or assigns to the United States any right he may have to share in money or other property received in satisfaction of the liability of the Panama Canal Company.