77 Pa. Stat. § 775
Whenever a claim petition or other petition is presented to the department, the department shall, by general rules or special order, assign it to a workers' compensation judge for hearing. When assigning petitions, including those for resolution hearings, the department shall not assign to a particular workers' compensation judge more than seventy-five per centum of the petitions from a particular county.
The department shall serve upon each adverse party a copy of the petition, together with a notice that such petition will be heard by the workers' compensation judge to whom it has been assigned (giving his name and address) as the case may be, and shall mail the original petition to such workers' compensation judge, together with copies of the notices served upon the adverse parties.
77 P.S. § 775