However, before making any determination, a Bureau of Workers’ Compensation claims service specialist (CSS) researches all claims to assure that all legal requirements for a claim have been met. Specifically, the CSS determines whether the worker’s injury or disease was directly caused by their employment. . Establishing causality relies on statements from the injured worker, their employer, and any witnesses. It also relies on viewing all medical evidence (i.e., progress notes, diagnostic reports, etc.) submitted by any treating providers.