20 CFR § 61.101 - Filing a request for reimbursement.
(a) A carrier or employer may file a request for reimbursement. The request shall be submitted to the U.S. Department of Labor, Office of Workers' Compensation Programs, Branch of Special Claims, P.O. Box 37117, Washington, DC 20013-7117;
(b) Each request for reimbursement shall include documentation itemizing the payments for which reimbursement is claimed. The documentation shall be sufficient to establish the purpose of the payment, the name of the payee, the date(s) for which payment was made, and the amount of the payment. Copies of any medical reports and bills related to medical examination or treatment for which reimbursement is claimed shall also be submitted. If the carrier cannot provide copies of the payment drafts or receipts, the Office may accept a certified listing of payments which includes payee name, description of services rendered, date of services rendered, amount paid, date paid check or draft number, and signature of certifier.
(1) Notice and claim forms;
(2) Statements of the employee or employer;
(3) Medical reports;
(4) Compensation orders; and
(5) Proof of liability (e.g., insurance policy or other documentation).