Investigate the appellant argument by interpreting applicable member benefits, Evidence of Coverage, benefit booklets, Summary Plan Descriptions, claims history, Explanation of Benefits, authorization records, denial rationale, medical and claim-payment policies, CMS guidance, state requirements, and IBX operational reference materials. • Prepare clear case notes, claim summaries, case narratives, and decision rationales that accurately explain the issue, research performed, evidence reviewed, applicable benefit or policy provisions, determination, and required next steps.