A Xactimate Supplement specialist typically reviews initial property loss estimates, identifies missing items or necessary repairs, and prepares supplemental claims using Xactimate software. They regularly communicate with insurance adjusters, restoration contractors, and property owners to gather documentation, justify supplements, and negotiate claim adjustments. Daily tasks often include site inspections, reviewing photos and reports, preparing detailed estimates, and maintaining accurate records in the claims management system. This role requires balancing fieldwork and office work to ensure claims are processed efficiently and accurately.