20 C.F.R. § 703.115
Every obligation and duty in respect of payment of compensation, the providing of medical and other treatment and care, the payment or furnishing of any other benefit required by said Act and in respect of the carrying out of the administrative procedure required or imposed by said Act or the regulations in this part upon an employer shall be discharged and carried out by the carrier except that the prescribed report of injury or death shall be sent by the employer to the district director and to the insurance carrier as required by 33 U.S.C. 930 . Such carrier shall be jointly responsible with the employer for the submission of all reports, notices, forms, and other administrative papers required by the district director or the Office in the administration of said Act to be submitted by the employer, but any form or paper so submitted where required therein shall contain in addition to the name and address of the carrier, the full name and address of the employer on whose behalf it is submitted. Notice to or knowledge of an employer of the occurrence of the injury or death shall be notice to or knowledge of such carrier. Jurisdiction of the employer by a district director, the Office, or appropriate appellate authority under said Act shall be jurisdiction of such carrier. Any requirement under any compensation order, finding, or decision shall be binding upon such carrier in the same manner and to the same extent as upon the employer.
20 C.F.R. § 703.115