77 Pa. Stat. § 751
If, after any injury, the employer or his insurer and the employe or his dependent, concerned in any injury, shall fail to agree upon the facts thereof or the compensation due under this act, the employe or his dependents may present a claim petition for compensation to the department.
In case any claimant shall die before the final adjudication of his claim, the amount of compensation due such claimant to the date of death shall be paid to the dependents entitled to compensation, or, if there be no dependents, then to the estate of the decedent.
Whenever any claim for compensation is presented and the only issue involved is the liability as between the defendant or the carrier or two or more defendants or carriers, the referee of the department to whom the claim in such case is presented shall forthwith order payments to be immediately made by the defendants or the carriers in said case. After the department's referee or the board on appeal, render a final decision, the payments made by the defendant or carrier not liable in the case shall be awarded or assessed against the defendant or carrier liable in the case, as costs in the proceedings, in favor of the defendant or carrier not liable in the case.
77 P.S. § 751